Reduce output of app install/upgrade script

templates/nextcloud-onlyoffice-config.yaml

@@ -106,7 +106,7 @@ data:
       # If the above url results in a 404, curl will not complain and store the
       # body of the 404 in the file :/. So we check here whether we actually
       # got a valid archive; `tar` will fail if not.
-      tar -tf "{{ .name }}.tar.gz"
+      tar -tf "{{ .name }}.tar.gz" >/dev/null
       # Remove old version of the app
       if [[ -d "$target_directory/{{ .name }}" ]]
       then