[BUGFIX] Add missing bracket in EXT:rtehtmlarea to fix syntax error

Resolves: #75541
Releases: 6.2
Change-Id: I2377695852fe6a307d0a4736f0f2e5eb4d79b608
Reviewed-on: https://review.typo3.org/47622


Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>