Panels are allowed to call programming rights API in the "create page" screen

To reproduce:
1/ Create a wiki panel that uses programming rights. A good content for the test is

{{velocity}}
$xwiki.hasProgrammingRights()
$xcontext.context.class
{{/velocity}}

2/ set this panel in a space
3/ it should display

false
$xcontext.context.class

because of issue XWIKI-6823.
4/ Go to an existing page in that space, the Add menu on top, choose "Page", you should be taken to the create page form
5/ the panel will display

true
class com.xpn.xwiki.XWikiContext

Which might mean that permissions are not properly dropped for create action. Since the create action in this situation (when the button is clicked from a document which exists) is executed in the context of the existing document, this might defy the purpose for which drop permissions is called.