roles/mariadb: Disable name lookups

Add skip-name-resolve=1 to disable lookups of hostnames to IPs. We
need to make sure all accounts are using IPs like 127.0.0.1 instead
of "localhost" now.

roles/mariadb/templates/my.cnf.j2

@@ -47,6 +47,10 @@ skip-external-locking
 # Instead of skip-networking the default is now to listen only on
 # localhost which is more compatible and is not less secure.
 bind-address		= 127.0.0.1
+
+# don't resolve connection IPs to hostnames (make sure user accounts are using
+# IPs instead of "localhost")
+skip-name-resolve=1
 #
 # * Fine Tuning
 #