How to make friends Nginx, Safari and http2?

Question

linux

After updating Nginx on the main server, I noticed that instead of spdy in hosts with ssl, you now have to specify http2. And with the same update, there was a problem with Safari on MacOS: internal requests in the interface, sent periodically in the background by the POST method, do not succeed: the browser gives the error "Failed to load resource: Failed to connect to the server" in the console.
As I understand it, this is related to the bug https://trac.nginx.org/nginx/ticket/959 - but I can hardly understand how I can fix it myself now (English is not at the highest level, in the ru-segment of descriptions of such found no problem).
On the old version of NGinx with spdy, everything worked, there is no way to roll back, I temporarily solved it by removing the http2 parameter from ssl hosts. NGinx itself is installed on Ubuntu from the repository https://launchpad.net/~nginx/+archive/ubuntu/stable