TT#47721 /etc/mysql/mariadb.cnf is needed for upgrades of mariadb

This file is needed for when mariadb-common invokes update-alternatives with
this file as argument, otherwise it aborts the upgrade and the system is left in
a broken state.

Change-Id: Icd42ab9d0def6bc3ccbdea307f5bc6416ec96fad

templates/133_filesys-deprecated.yaml.tt2

@@ -16,10 +16,6 @@ file:
     exists: false
     filetype: directory
 
-  /etc/mysql/mariadb.cnf:
-    exists: false
-    filetype: file
-
   /etc/mysql/my.cnf.fallback:
     exists: false
     filetype: file