Fix Fluentd date format for MariaDB xinetd

Time format in Ruby Time.strptime is not accepting padding flags,
therefore we need to remove them for the Fluentd to be able
to parse MariaDB xinetd logs properly.

Change-Id: Iabfa9afdcad505106a5580eb2d058273ee5f7c1f
Closes-Bug: #1886002

ansible/roles/common/templates/conf/input/02-mariadb.conf.j2

@@ -20,7 +20,7 @@
   format1 /^(?<Timestamp>\S+) (?<Payload>.*)?$/
   time_key Timestamp
   keep_time_key true
-  time_format %y/%-m/%-d@%T
+  time_format %y/%m/%d@%T
   ignore_repeated_permission_error true
   enable_watch_timer false
 </source>