[webvtt] Mark text-combine-upright as at risk (#456)

nigelmegitt has just created a new issue for https://github.com/w3c/webvtt:

== Mark text-combine-upright as at risk ==
As discussed in today's call.

Please view or discuss this issue at https://github.com/w3c/webvtt/issues/456 using your GitHub account

Received on Thursday, 13 June 2019 15:46:49 UTC