mysql/postgres: fix warning that when uses raw variables

mysql/tasks/main.yml

@@ -25,7 +25,7 @@
     enabled: true
 
 - name: setup mysql backups with rsnapshot
-  when: '{{ mysql_rsnapshot }}'
+  when: mysql_rsnapshot
   block:
     - name: ensure a read-only mysql user for backups exists
       mysql_user:

postgres/tasks/main.yml

@@ -37,7 +37,7 @@
     enabled: true
 
 - name: configure snapshots
-  when: '{{ postgres_rsnapshot }}'
+  when: postgres_rsnapshot
   block:
     - name: ensure we have our postgres backup script
       copy: