Re-enable HMRC web chat on self assessment URLs
Re-enable HMRC web chat on self assessment URLs

HMRC have asked us to re-enable their web chat trial on various
self-assessment related URLs. These were originally removed in #c8a0440.
alphagov/static,alphagov/static,kalleth/static,kalleth/static,alphagov/static,kalleth/static,kalleth/static