fixed potential passing of deleted item to sendChatItem when a ChatLobbyItem is too big (would probably cause a crash. Found using coverity)

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@8428 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/chat/distributedchat.cc

@@ -388,6 +388,7 @@ void DistributedChatService::checkSizeAndSendLobbyMessage(RsChatItem *msg)
     {
         std::cerr << "(EE) Chat item exceeds maximum serial size. It will be dropped." << std::endl;
         delete msg ;
+    return ;
     }
     sendChatItem(msg) ;
 }