Add an empty exec option to the mysql command so than the shell can exit

Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>

db/mysql/mysql_service.inc

@@ -88,7 +88,7 @@ class provisionService_db_mysql extends provisionService_db_pdo {
   }
   
   function grant_host(provisionContext_server $server) {
-    $command = sprintf('mysql -u intntnllyInvalid -h %s -P %s',
+    $command = sprintf('mysql -u intntnllyInvalid -h %s -P %s -e ""',
       escapeshellarg($this->server->remote_host),
       escapeshellarg($this->server->db_port));