Revert "[BUGFIX] Throw Exception if typo3 extension repository is not defined"

This reverts commit 130a840d90d99bbb27a5f3f603d6b06db933b13f

Change-Id: I7e3494ec83d0f4acb588f556970a3a91f60df904
Reviewed-on: https://review.typo3.org/19651
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn