Dungeon Finder: Add config value to Enable/Disable Dungeon Finder

Note: Default value = Disable (while is WIP)

--HG--
branch : trunk

src/server/game/Server/Protocol/Handlers/LFGHandler.cpp

@@ -25,6 +25,11 @@
 void WorldSession::HandleLfgJoinOpcode(WorldPacket &recv_data)
 {
     sLog.outDebug("CMSG_LFG_JOIN");
+    if (!sWorld.getConfig(CONFIG_DUNGEON_FINDER_ENABLE))
+    {
+        recv_data.rpos(recv_data.wpos());
+        return;
+    }
 
     uint8 numDungeons;
     uint32 dungeon;