Optimized nginx CSP (prop. leads to problems due to too high restrictions for some roles) and implemented health check for mailer

roles/backup-remote-to-local/templates/backups-remote-to-local.sh.j2

@@ -1,8 +1,8 @@
 #!/bin/bash
 # Pulls the remote backups from multiple hosts
-hosts="{{pull_remote_backups}}";
+hosts="{{ pull_remote_backups | join(' ') }}";
 errors=0
 for host in $hosts; do
-  bash {{docker_backup_remote_to_local_folder}}backup-remote-to-local.sh $host || ((errors+=1));
+  bash {{ docker_backup_remote_to_local_folder }}backup-remote-to-local.sh $host || ((errors+=1));
 done;
 exit $errors;