Yeah had that also.
I updated the apk and it is in Jolla Harbour verification process right now.
I don't think it will be approved today or tomorrow. Maybe the day after tomorrow.
(I guess they still have people there working until the end of the year)

As for now if you need it you can also install it from here:
https://app.box.com/s/0l48h01j368u43e7shfiwghld4dt9f9b

Btw. this is a big update as it includes the renaming to Signal. (originally upstream merged RedPhone and TextSecure to Signal)

This means generally you have also encrypted call support. But it crashes on me here. Might be that it needs some upstream approval after several days on the server for it to work though.