[BUGFIX] Add missing styles.content.links constants

[BUGFIX] Add missing styles.content.links constants

Resolves: #70324
Releases: master
Change-Id: I6a499b48d6e1467fa46ed09370d7f8ffabb34844
Reviewed-on: http://review.typo3.org/43768
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Alexander Grein <alexander.grein@gmail.com>
Tested-by: Alexander Grein <alexander.grein@gmail.com>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>