[BUGFIX] Remove Closure in signalSlotDispatcher

As the classAliasMap is a singleton we don't need to initialize it on
every dispatch, but we can call the method directly on the instance.
This prevents a closure for signalSlotDispatcher which otherwise throws
an exception on serialization.

Releases: master
Resolves: #65473
Change-Id: I1280a4a054f3b63b4b5e71262d4d054b511f001b
Reviewed-on: http://review.typo3.org/37485


Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>