announcement-mail broken when NOT using the announcementFile parameter

When using a custom template to generate an announcement, the goal announcement-mail will fail if :

• I provide the parameters template (other than announcement.vm) and templateDirectory
• and I don't provide the parameter announcementFile

Trace :

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-changes-plugin:2.10:announcement-mail (default-cli) on project test-changes-sendmail: Announcement file D:\Projets\Workspace_projets_java\test-changes-sendmail\target\announcement\announcement.vm not found... -> [Help 1]

This is a regression : it worked with version 2.9
Related to MCHANGES-280