Ignore StateElementReferenceExceptions in waitUntil

Change-Id: Ic3961afb19187df9bb603bc1be787e936771c20d
Reviewed-on: https://pirx.atteo.com/gerrit/615
Reviewed-by: Sławek Piotrowski <sentinel@atteo.com>
Tested-by: Mr. Jenkins
Merge remote-tracking branch 'official/master'