Make explicit that the backup process is about the Plasma Mobile rootfs

1 job for master in 37 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Deploy
failed #3821
pages

00:00:37

 
Name Stage Failure
failed
pages Deploy
Setting up libpopt0:amd64 (1.16-10+b2) ...
Setting up rsync (3.1.2-1+deb9u1) ...
invoke-rc.d: could not determine current runlevel
invoke-rc.d: policy-rc.d denied execution of restart.
Processing triggers for libc-bin (2.24-11+deb9u4) ...
$ eval $(ssh-agent -s)
Agent pid 249
$ echo "$SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null
Enter passphrase for (stdin):
ERROR: Job failed: exit code 1