Remove internaledit, externaledit, mode params from My* special pages 

The corresponding code was removed with
Ic3791d188688f556753ab5556a4d9733bbf2e85e, so there is no need to allow
these params on such redirects.
The redirect will not break, only the param is removed from request.

Change-Id: Ibb85bf3b23c9d17336f0a8b37a7315da8dcb7eef