Edit Class menu entry appears only for admin users

While the class editor is accessible by direct URL to any user (obviously, as long as he has edit rights on the page), the "Edit Class" menu entries is displayed only to users with admin rights.

See

• https://github.com/xwiki/xwiki-platform/blob/master/xwiki-platform-core/xwiki-platform-web/src/main/webapp/templates/editmenu.vm#L18
• https://github.com/xwiki/xwiki-platform/blob/master/xwiki-platform-core/xwiki-platform-web/src/main/webapp/templates/contentmenu.vm#L19

Any user should be able to see the class editor as long as he has edit rights on the page.