[BUGFIX] Move TCA modification of EXT:felogin to TCA/Overrides.

TCA manipulation code must no longer reside in ext_tables.php, but
moved to Configuration/TCA/Overrides/<tablename>.php. Leftovers
in ext_tables might disturb loading order of TCA changes and spoil
proper caching.

Resolves: #59462
Related: #59414
Releases: 6.3,6.2
Change-Id: I0bd42865f199b7fcccc1ee9133776271a1af2bcd
Reviewed-on: https://review.typo3.org/31347
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters