Only configure postgres snapshots with rsnapshot

postgres/tasks/main.yml

@@ -36,6 +36,9 @@
     state: started
     enabled: true
 
+- name: configure snapshots
+  when: '"servers_rsnapshot" in group_names'
+  block:
     - name: ensure we have our postgres backup script
       copy:
         src: "pgbackup{{ '-bullseye' if ansible_distribution_major_version|int(default=99) > 10 else '' }}.sh"