Make shellcheck happy

.gitlab/ci_scripts/create_vps.sh

@@ -3,15 +3,19 @@
 
 set -ve
 
+# shellcheck disable=SC2039
+HOST_NAME="$HOSTNAME"
+
 # Delete old machine if it still exists
 echo "Deleting old machine"
-python3 -c "import greenhost_cloud; greenhost_cloud.terminate_droplets_by_name(\"^${HOSTNAME}$\")"
+python3 -c "import greenhost_cloud;
+greenhost_cloud.terminate_droplets_by_name(\"^${HOST_NAME}$\")"
 echo "Creating new machine"
 # Uses a custom disk image built with 1f2bee2 on 2021-10-19. See
 # CONTRIBUTING.md#ci-pipeline-image for more info.
-python3 -m openappstack $HOSTNAME create \
+python3 -m openappstack "$HOST_NAME" create \
   --create-droplet "$DOMAIN" \
-  --create-hostname "$HOSTNAME" \
+  --create-hostname "$HOST_NAME" \
   --ssh-key-id "$SSH_KEY_ID" \
   --create-domain-records \
   --subdomain "$SUBDOMAIN" \