Missing CSRF token causes warning that the content will be executed in restricted mode to be displayed when creating a test

Steps to reproduce

1. In the Test Reporting App, click "Add Test" button (on the app's home page) or "Add new Test" (on a space page)
2. Insert a name of a new test (and, if the case, the space name)
3. Click "Add a new Test" button

Expected results

No warning is displayed on the top of the page.

Actual results

The following warning is displayed:

Warning: For security reasons, the 
content of the edited document is executed in restricted mode, as the 
edit was not  initiated by a validated request. There may be unexpected 
errors due to this.

The issue seems to reproduce since xwiki.org was upgraded to XWiki 14.10.11 (tested locally and reproduced also on XWiki 15.5).