[BUGFIX] Reset InternalRequestEngine for each functional test
Currently all functional tests share the same instance of
\TYPO3\FLOW3\Mvc\Routing\Router because the InternalRequestEngine
is of scope singleton.
This leads to unexpected results and failing tests if tests add
This change fixes this by making the ObjectManager forget the
singleton instance of the request engine after each testrun.
This also reverts the changes that were introduced with
I5a5bf17d00c5be05748a18122dae42989f429221 as they did not
have the expected effect.
Releases: 1.1, 1.2