WireGuard fails to build on CentOS 7.1908

[Jason A. Donenfeld]

Hey Dario,

Thanks for the explanation. I released a new snapshot today that
should include support for both RHEL 7.6 and 7.7. As soon as CentOS
7.7 comes out, I intend to drop 7.6 support entirely to continue with
the policy of supporting the latest RHEL only. It seems like there's
an awkward transition period while CentOS catches up to RHEL, so I'll
try to stay on top of that for 7.7->7.8 too.

Joe - can you bump the copr package?

Jason