[TASK] Replace icon by IconFactory: actions-system-backend-user-switch

Resolves: #69672
Releases: master
Change-Id: I32d97d57d0abdaa6214a0edda2e034c35cbd3906
Reviewed-on: http://review.typo3.org/43211


Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>