[BUGFIX] RTE: insert table broken

Opening any dialogue window raises a JS error.

Releases: master
Resolves: #63682
Change-Id: I5c1bee6785a350fc3328e930109653161139d918
Reviewed-on: http://review.typo3.org/35169
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>