Fixed linux compilation error with linker

This was caused by a GNUC compiler optimization that removes
LFG.obj from binaries since its functions have never been called
by gamelib. So we had to call at least one of them on LFGMgr forcing
 compiler to include LFG.cpp in build. I can't find another way.

src/scripts/Commands/cs_lfg.cpp

@@ -72,7 +72,7 @@ public:
             handler->PSendSysMessage(LANG_LFG_NOT_IN_GROUP, playerName.c_str());
             return true;
         }
-        /*
+
         uint64 guid = grp->GetGUID();
         std::string const& state = lfg::GetStateString(sLFGMgr->GetState(guid));
         handler->PSendSysMessage(LANG_LFG_GROUP_INFO, grp->isLFGGroup(),
@@ -80,7 +80,7 @@ public:
 
         for (GroupReference* itr = grp->GetFirstMember(); itr != nullptr; itr = itr->next())
             GetPlayerInfo(handler, itr->GetSource());
-        */
+
         return true;
     }