remove old copr playbooks

run them now as:
rbac-playbook groups/copr-frontend.yml
run playbooks only for copr-prod for this moment
copr: fixing path to cron-backup-database
run playbooks only for copr-prod for this moment
mv ./roles/copr/backend/files/keystonerc  ./roles/copr/backend/templates/
add signer_host variable

addressing:
TASK: [copr/backend | add  sign machine address into the  sign.conf] **********
fatal: [copr-be.cloud.fedoraproject.org] => One or more undefined variables: 'signer_host' is undefined
Add getfedora.org