Re-indent some libs and scripts, change 4 to 2-space indent

Mostly found with:

    for i in nselib/*.lua scripts/*.nse; do
      echo $(perl -lne 'BEGIN{$a=$p=0}next unless $_;/^(\s*)/;' \
        -e '$l=length$1;next if$l==$p;$a+=(abs($l-$p)-$a)/$.;' \
        -e '$p=$l;END{print$a}' $i) $i
    done | sort -nr

And indented with: https://gist.github.com/bonsaiviking/8845871

whois-ip.nse was particularly mangled (probably my fault due to using
vim's built-in indentation script, but it could be structured better)

scripts/http-useragent-tester.nse

@@ -56,29 +56,29 @@ local string = require "string"
 
 getLastLoc = function(host, port, useragent)
 
-    local options
+  local options
 
-    options = {header={}, no_cache=true, redirect_ok=function(host,port)
-        local c = 3
-        return function(url)
-            if ( c==0 ) then return false end
-                c = c - 1
-                return true
-            end
-        end }
+  options = {header={}, no_cache=true, redirect_ok=function(host,port)
+      local c = 3
+      return function(url)
+        if ( c==0 ) then return false end
+        c = c - 1
+        return true
+      end
+  end }
 
 
-    options['header']['User-Agent'] = useragent
+  options['header']['User-Agent'] = useragent
 
-    stdnse.print_debug(2, "Making a request with User-Agent: " .. useragent)
+  stdnse.print_debug(2, "Making a request with User-Agent: " .. useragent)
 
-    local response = http.get(host, port, '/', options)
+  local response = http.get(host, port, '/', options)
 
-    if response.location then
-        return response.location[#response.location] or false
-    end
+  if response.location then
+    return response.location[#response.location] or false
+  end
 
-    return false
+  return false
 
 end
 
@@ -86,70 +86,70 @@ portrule = shortport.port_or_service( {80, 443}, {"http", "https"}, "tcp", "open
 
 action = function(host, port)
 
-    local moreagents = stdnse.get_script_args("http-useragent-tester.useragents") or nil
-    local newtargets = stdnse.get_script_args("newtargets") or nil
+  local moreagents = stdnse.get_script_args("http-useragent-tester.useragents") or nil
+  local newtargets = stdnse.get_script_args("newtargets") or nil
 
-    -- We don't crawl any site. We initialize a crawler to use its iswithinhost method.
-    local crawler = httpspider.Crawler:new(host, port, '/', { scriptname = SCRIPT_NAME } )
+  -- We don't crawl any site. We initialize a crawler to use its iswithinhost method.
+  local crawler = httpspider.Crawler:new(host, port, '/', { scriptname = SCRIPT_NAME } )
 
-    local HTTPlibs = {"libwww",
-                "lwp-trivial",
-                "libcurl-agent/1.0",
-                "PHP/",
-                "Python-urllib/2.5",
-                "GT::WWW",
-                "Snoopy",
-                "MFC_Tear_Sample",
-                "HTTP::Lite",
-                "PHPCrawl",
-                "URI::Fetch",
-                "Zend_Http_Client",
-                "http client",
-                "PECL::HTTP",
-                "Wget/1.13.4 (linux-gnu)",
-                "WWW-Mechanize/1.34"
-                }
+  local HTTPlibs = {"libwww",
+    "lwp-trivial",
+    "libcurl-agent/1.0",
+    "PHP/",
+    "Python-urllib/2.5",
+    "GT::WWW",
+    "Snoopy",
+    "MFC_Tear_Sample",
+    "HTTP::Lite",
+    "PHPCrawl",
+    "URI::Fetch",
+    "Zend_Http_Client",
+    "http client",
+    "PECL::HTTP",
+    "Wget/1.13.4 (linux-gnu)",
+    "WWW-Mechanize/1.34"
+  }
 
-    if moreagents then
-       for _, l in ipairs(moreagents) do
-            table.insert(HTTPlibs, l)
+  if moreagents then
+    for _, l in ipairs(moreagents) do
+      table.insert(HTTPlibs, l)
+    end
+  end
+
+  -- We perform a normal browser request and get the returned location
+  local loc = getLastLoc(host, port, "Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.57 Safari/537.17")
+
+  local allowed, forb = {}, {}
+
+  for _, l in ipairs(HTTPlibs) do
+
+    local libloc = getLastLoc(host, port, l)
+
+    -- If the library's request returned a different location, that means the request was redirected somewhere else, hence is forbidden.
+    if loc ~= libloc then
+      local msg = l .. " redirected to: " .. libloc
+      local libhost = http.parse_url(libloc)
+      if not crawler:iswithinhost(libhost.host) then
+        msg = msg .. " (different host)"
+        if newtargets then
+          target.add(libhost.host)
         end
+      end
+      table.insert(forb, msg)
+    else
+      table.insert(allowed, l)
     end
 
-    -- We perform a normal browser request and get the returned location
-    local loc = getLastLoc(host, port, "Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.57 Safari/537.17")
+  end
 
-    local allowed, forb = {}, {}
+  if next(allowed) ~= nil then
+    table.insert(allowed, 1, "Allowed User Agents:")
+  end
 
-    for _, l in ipairs(HTTPlibs) do
+  if next(forb) ~= nil then
+    table.insert(forb, 1, "Forbidden User Agents:")
+  end
 
-        local libloc = getLastLoc(host, port, l)
-
-        -- If the library's request returned a different location, that means the request was redirected somewhere else, hence is forbidden.
-        if loc ~= libloc then
-            local msg = l .. " redirected to: " .. libloc
-            local libhost = http.parse_url(libloc)
-            if not crawler:iswithinhost(libhost.host) then
-                msg = msg .. " (different host)"
-                if newtargets then
-                    target.add(libhost.host)
-                end
-            end
-            table.insert(forb, msg)
-        else
-            table.insert(allowed, l)
-        end
-
-    end
-
-    if next(allowed) ~= nil then
-        table.insert(allowed, 1, "Allowed User Agents:")
-    end
-
-    if next(forb) ~= nil then
-        table.insert(forb, 1, "Forbidden User Agents:")
-    end
-
-    return {allowed, forb}
+  return {allowed, forb}
 
 end