Fix require for mysql_service

Starting with [0] grains are provided via salt-formula metadata.
This patch removes broken require for mysql_service as 'mysql_salt_config'
is not defined any more.

[0] https://gerrit.mcp.mirantis.net/4297/

Change-Id: Id7acea75161ea79259f00df4081dcda844119f58
1 file changed