Require the powershell mixin explicitly

Author: Tod Beardsley

modules/exploits/windows/http/oracle_endeca_exec.rb

@@ -6,6 +6,7 @@
 ##
 
 require 'msf/core'
+require 'msf/core/exploit/powershell'
 
 class Metasploit3 < Msf::Exploit::Remote
 	Rank = ExcellentRanking