Pull the deploying app image name where necessary

All of these commands should execute against the image that is in use versus the "latest" that dokku provides the system with.

plugins/nginx-vhosts/functions

@@ -141,7 +141,7 @@ get_custom_nginx_template() {
   local APP="$1"; verify_app_name "$APP"
   local DESTINATION="$2"
   local IMAGE_TAG="$(get_running_image_tag "$APP")"
-  local IMAGE=$(get_app_image_name "$APP" "$IMAGE_TAG")
+  local IMAGE=$(get_deploying_app_image_name "$APP" "$IMAGE_TAG")
   local NGINX_TEMPLATE_NAME="nginx.conf.sigil"
 
   copy_from_image "$IMAGE" "$NGINX_TEMPLATE_NAME" "$DESTINATION" 2>/dev/null || true