borg-backup: disambiguate for multiple servers

The ssh config and cron job will overwrite each other when we have
multiple backup servers.

Ensure the markers are different.

Change-Id: I1736fa9c72c90a357b2229bc86c33b33a2bb321c

playbooks/roles/borg-backup/tasks/main.yaml

@@ -33,7 +33,7 @@
       IdentityFile /root/.ssh/id_borg_backup_ed25519
       User {{ borg_username }}
     mode: 0600
-    marker: '# {mark} ANSIBLE MANAGED BLOCK borg-backup'
+    marker: '# {mark} ANSIBLE MANAGED BLOCK borg-backup {{ item }}'
   with_inventory_hostnames: borg-backup-server
 
 - name: Generate borg_user info tuple
@@ -49,7 +49,7 @@
 
 - name: Install backup cron job
   cron:
-    name: "Run borg backup"
+    name: "Run borg backup to {{ item }}"
     job: "/usr/local/bin/borg-backup {{ item }} 2>> /var/log/borg-backup-{{ item }}.log"
     user: root
     hour: '5'