[BUGFIX] YouTubeRenderer: urlencode the origin parameter

Commit 84ab4133 (https://review.typo3.org/49416) fixed the origin
parameter to include the full host (and thus the scheme).
The full host url was not urlencoded. As the scheme contains
slashes this has to be encoded as well.

Change-Id: Ifb73dfc11ef723049729e0475eb6ac234db6a3eb
Releases: master, 7.6
Resolves: #78728
Reviewed-on: https://review.typo3.org/50686


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>