[BUGFIX] Web>Page gridColumn outter spacing

Fix grid column container width to reach 100% without previous
gap on the right side.

Resolves: #63202
Releases: master
Change-Id: I2508505e255542f751463c95195df4497beb76fd
Reviewed-on: http://review.typo3.org/34803
Reviewed-by: Christoph Hofmann <typo3@its-hofmann.de>
Tested-by: Christoph Hofmann <typo3@its-hofmann.de>
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>