File named '.nxftl' in configuration template is not allowed

How to reproduce:

• create a custom configuration template (as described in Configuration Templates and create an empty file named .nxftl in its config directory (OR use an existing one)
• add the name of the template to the nuxeo.templates variable in your nuxeo.conf
• start the Nuxeo Platform

The startup will fail with the error message Could not run configuration: Configuration failure: Source '/opt/nuxeo/server/nxserver/config' exists but is a directory