[BUGFIX] Fix sorting extensions in "Get Extensions" module

During some Doctrine cleanup the constraint for fetching extension by
extension key got messed up. This patch removes double named parameter
in search constraint.

Resolves: #80555
Releases: master, 8.7
Change-Id: I84636b4a86d8b3946c552031e3cb23ae69cd3f2a
Reviewed-on: https://review.typo3.org/54699


Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>