[TASK] Deprecate $disable Option in PageRepository->getExtURL

[TASK] Deprecate $disable Option in PageRepository->getExtURL

The disable option to check whether redirects are allowed
should be handled outside of the call to simplify code readability
and maintainability.

Resolves: #66904
Releases: master
Change-Id: Ica85c0703641ff4764233b626d0c08a64bb65d28
Reviewed-on: http://review.typo3.org/39473
Reviewed-by: Frank Nägler <frank.naegler@typo3.org>
Tested-by: Frank Nägler <frank.naegler@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>