Lua 5.2 upgrade [1] for NSE.

[1] http://seclists.org/nmap-dev/2012/q2/34

scripts/http-malware-host.nse

@@ -1,3 +1,10 @@
+local http = require "http"
+local nmap = require "nmap"
+local shortport = require "shortport"
+local stdnse = require "stdnse"
+local string = require "string"
+local table = require "table"
+
 description = [[
 Looks for signature of known server compromises.
 
@@ -27,9 +34,6 @@ license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
 
 categories = {"malware", "safe"}
 
-require 'http'
-require 'shortport'
-require 'stdnse'
 
 portrule = shortport.http