Core/Dungeon Finder: Restore consistency after an inconsistency is found while checking compatibilities

Closes issue 3950

--HG--
branch : trunk

src/server/game/DungeonFinding/LFGMgr.cpp

@@ -827,6 +827,7 @@ bool LFGMgr::CheckCompatibility(LfgGuidList check, LfgProposalList *proposals)
         if (itQueue == m_QueueInfoMap.end())
         {
             sLog.outError("LFGMgr::CheckCompatibility: [" UI64FMTD "] is not queued but listed as queued!", *it);
+            RemoveFromQueue(*it);
             return false;
         }
         pqInfoMap[*it] = itQueue->second;