net-p2p/xbt: unbreak the build and update to the latest GitHub snapshot
- Revert some changes made upstream so we stay compatible with C++17
- Do not increase UDP sent packets counter if sendto() call failed
- Don't try to be smart and assume BSD make (see commit 3129c2094ecb for detailed explanation)
- Use more accurate values for WWW and BUILD_DEPENDS, add PORTSCOUT
Reported by: pkg-fallout