Revert "try with normal disk image instead of k3s template"

This reverts commit 61f2e331.

.gitlab/ci_scripts/create_vps.sh

@@ -17,5 +17,5 @@ python3 -m openappstack $HOSTNAME create \
   --ssh-key-id $SSH_KEY_ID \
   --create-domain-records \
   --subdomain $SUBDOMAIN \
-  --disk-image-id 19 \
+  --disk-image-id '-7121' \
   --truncate-subdomain