[BUGFIX] Re-enable indexed_search $TCA for index_config

EXT: indexed_search $TCA for table index_config is only loaded
when EXT: crawler is installed but $TCA must always be included.
Removes condition to limit $TCA inclusion.

Change-Id: I9768ae18c40fa95084fbca54880ffc7b31e1f0a1
Fixes: #32815
Releases: 4.7, 6.0
Reviewed-on: http://review.typo3.org/11145
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter