Description of problem:
During the trial run of backup and recovery of Satellite server by (katello-backup|restore), system could NOT recover the Remote Execution function
because the ssh private key (/usr/share/foreman-proxy/.ssh/id_rsa_foreman_proxy) was not backed up.

Version-Release number of selected component (if applicable):
satellite 6.2.12

How reproducible:
Always

Steps to Reproduce:
1. Run katello-backup
2. Try to restore from the back up
3. Rex will not work on restored system as ssh-keys were not backed up

Actual results:
ssh-key not available in backup in katello-backup

Expected results:
ssh-key should be backed up in katello-backup or there should be some option to enable it