bug 442473: Menu on disabled row not possible 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=442473

Change-Id: I1d236ebbdc09b29fbadbc8fa761df1aeac330bca
Reviewed-on: https://git.eclipse.org/r/34690
Tested-by: Hudson CI
Reviewed-by: Andreas Hoegger <Andreas.Hoegger@bsiag.com>