Removed client hangup error message

The error message did not provide any useful information and was most of the
time a false positive due to EPOLL_RDHUP events calling the hangup function
of the DCB.

server/modules/protocol/mysql_client.c

@@ -1866,13 +1866,7 @@ gw_client_hangup_event(DCB *dcb)
         {
                 goto retblock;
         }
-#if defined(SS_DEBUG)
-        LOGIF(LE, (skygw_log_write_flush(
-            LOGFILE_ERROR,
-            "Client hangup error handling, session state %s, dcb state %s.",
-            session_state(session->state),
-            STRDCBSTATE(dcb->state))));
-#endif
+
         dcb_close(dcb);
  
 retblock: