Small linting and whitespace fixes

roles/borg_client/templates/backup-my.cnf.j2

 [client]
 user = root
-password = "{{vault_mariadb_users.root}}"
+password = "{{ vault_mariadb_users.root }}"

roles/borg_client/templates/backup-postgres.sh.j2

 #!/bin/bash
 #
 # Script to backup all postgres databases individually
-# 
+#
 # Requires local login with `postgres` user and either trusted or peer auth.
 #