More verbose output if KILL fails

lib/MySQL_Session.cpp

@@ -148,6 +148,7 @@ void * kill_query_thread(void *arg) {
 		ret=mysql_real_connect(mysql,"localhost",ka->username,ka->password,NULL,0,ka->hostname,0);
 	}
 	if (!ret) {
+		proxy_error("Failed to connect to server %s:%d to run KILL %s %llu: Error: %s\n" , ka->hostname, ka->port, ( ka->kill_type==KILL_QUERY ? "QUERY" : "CONNECTION" ) , ka->id, mysql_error(mysql));
 		goto __exit_kill_query_thread;
 	}
 	char buf[100];