Commit https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d2c5c103b1337f590b7edf1509a6e294bdf22402 removed net/netfilter/nf_nat_core.h, which breaks wireguard builds for 5.1.0-0.rc0.git5.2.fc31.x86_64. It sounds like it isn't needed any more from the commit message.