[TASK] Remove unneeded explicit parameter when loading ext_tables.php

The Bootstrap takes an optional parameter whether the
extension tables files should be cached or not.

The default case is "true" and does not need to be set explicitly.

Resolves: #72483
Releases: master
Change-Id: I9c9403537005a7ad56acdc2dbb4b482134fe7567
Reviewed-on: https://review.typo3.org/45508


Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>