Bug 571100 - Fix JFace Viewer Controls not updating on domainModelChange

When the cache is enabled, enum controls do not update when switching
elements.
This is due to a missing super call of rootDomainModelChanged .

Change-Id: I21231b23603ce576fc34f332cab659976ddb8dc6
Signed-off-by: Eugen Neufeld <eneufeld@eclipsesource.com>