[BUGFIX] RTE toolbar layout broken

Toolbar elements do not wrap correctly.

Releases: master
Resolves: #62710
Change-Id: Iefba035219c46baf3b481547d990c80b04924430
Reviewed-on: http://review.typo3.org/33808
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>