copr-builder: don't give up RHSM unregistering

This way we have less work in the periodic cron job
(see cleanup-unused-redhat-subscriptions script).

roles/copr/backend/templates/resalloc/vm-delete.j2

@@ -6,7 +6,12 @@ test -z "$RESALLOC_NAME" && die "no vm specified, empty \$RESALLOC_NAME variable
 
 # Try to, best effort, remove the entitlement.
 set -- $(echo "$RESALLOC_RESOURCE_DATA" | base64 --decode)
-ssh root@"$1" "subscription-manager unregister" || :
+
+# Don't give-up unregistering after the first attempt
+for _ in a b c; do
+    ssh root@"$1" "subscription-manager unregister" && break
+    sleep 5
+done
 
 case "$RESALLOC_POOL_ID" in
 *aws*)