BUG: Remove the is_null check on augmentValidURLSegment
BUG: Remove the is_null check on augmentValidURLSegment

Object::extend already does a check for NULL before it adds the results
to the array of return values. This was required for Translatable as the
result from Translatable::augmentValidURLSegment was being ignored.

silverstripe/silverstripe-cms,silverstripe/silverstripe-siteconfig,dhensby/silverstripe-cms,silverstripe-labs/silverstripe-reports,jonom/silverstripe-cms,helpfulrobot/i-lateral-silverstripe-siteconfig,jonom/silverstripe-cms,dhensby/silverstripe-reports,dhensby/silverstripe-cms,silverstripe/silverstripe-cms,dhensby/silverstripe-reports,silverstripe-labs/silverstripe-reports,dhensby/silverstripe-cms