[BUGFIX] Always disable jumpurl for external media

We always disable the global jumpurl feature when retrieving the URL for
an external media element like a video.

Resolves: #63807
Releases: master, 6.2
Change-Id: I3c108f4366869e39423bf1121ee7dfa125148a2a
Reviewed-on: http://review.typo3.org/35372
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>