Add missing requires.

nselib/data/http-default-accounts-fingerprints.lua

@@ -1,3 +1,7 @@
+local http = require "http"
+local table = require "table"
+local url = require "url"
+
 ---
 -- http-default-accounts-fingerprints.lua
 -- This file contains fingerprint data for http-default-accounts.nse

nselib/data/http-fingerprints.lua

@@ -1,3 +1,5 @@
+local table = require "table"
+
 ---HTTP Fingerprint files, compiled by Ron Bowes with a special thanks to...
 -- o Kevin Johnson (@secureideas) for the fingerprints that come with Yokoso
 --   http://yokoso.inguardians.com

nselib/data/packetdecoders.lua

@@ -1,3 +1,9 @@
+local bin = require "bin"
+local packet = require "packet"
+local stdnse = require "stdnse"
+local tab = require "tab"
+local target = require "target"
+
 --- The following file contains a list of decoders used by the
 -- broadcast-listener script. A decoder can be either "ethernet" based or IP
 -- based. As we're only monitoring broadcast traffic (ie. traffic not