Page blueprint doesn't auto-fill variables after edited

Issue Summary

After editing a page template (blueprint) which auto-fill fields, such as the Retrospective blueprint, the fields won't be automatically filled (Date, Team, Participants)

Steps to Reproduce

1. Go to /wiki/pages/templates2/listglobaltemplates.action/ and edit the Retrospective blueprint
2. Insert any text and Save it (don't remove the exiting contents)
3. Create a page using the blueprint

Expected Results

It should automatically fill the Date, Team and Participants fields

Actual Results

The Date, Team and Participants fields will be empty when creating the page

Workaround

Either revert the template to the default one or manually fill those fields.