main.lock_kill fails in embedded

when killing a query in a parallel connection, disable warnings.
Because --error doesn't apply to automatically sent SHOW WARNINGS,
so if KILL arrives at the right moment the test will fail with

mysqltest: At line 41: Error running query "SHOW WARNINGS": Server has gone away

mysql-test/main/lock_kill.test

@@ -17,8 +17,10 @@ LOCK TABLE t1 WRITE;
 eval KILL $conid;
 --enable_query_log
 --connection con1
+--disable_warnings
 --error 0,2006,2013,ER_CONNECTION_KILLED
 reap;
+--enable_warnings
 --connection default
 --disconnect con1
 DROP TABLE t1;
@@ -35,8 +37,10 @@ LOCK TABLE t1 WRITE, t2 WRITE;
 eval KILL $conid;
 --enable_query_log
 --connection con1
+--disable_warnings
 --error 0,2006,2013,ER_CONNECTION_KILLED
 reap;
+--enable_warnings
 --connection default
 --disconnect con1
 DROP TABLE t1, t2;