[BUGFIX] Page module Quickedit: wizards are broken

When using Quickedit mode of Page module, the header link and the RTE
wizards are broken.
Backpath is added twice to the wizard urls.

Releases: master, 6.2
Resolves: #60958
Change-Id: I9ad470f9b7ffd4b74a91e02c4be2615723e79fd3
Reviewed-on: http://review.typo3.org/33820
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Benjamin Mack <benni@typo3.org>