Fix some mistakes pointed by @wchen-r7

Author: jvoisin

modules/exploits/unix/webapp/vbulletin_unserialize.rb

@@ -46,8 +46,8 @@ def initialize(info = {})
   end
 
   def check
-    res = send_request_cgi({ 'uri' => '/' })
-    if (res && res.body =~ /Version 5.1./ && res.body =~ /Copyright © 2015 vBulletin Solutions, Inc./)
+    res = send_request_cgi({ 'uri' => target_uri.path })
+    if (res && res.body.include?("Version 5.1.") && res.body.include?('Copyright © 2015 vBulletin Solutions, Inc.'))
       return Exploit::CheckCode::Appears
     else
       return Exploit::CheckCode::Unknown