MINOR: quic: do not crash on unhandled sendto error

Remove ABORT_NOW() statement on unhandled sendto error. Instead use a
dedicated counter sendto_err_unknown to report these cases.

If we detect increment of this counter, strace can be used to detect
errno value :
  $ strace -p $(pidof haproxy) -f -e trace=sendto -Z

This should be backported up to 2.6.

This should help to debug github issue #1903.
2 files changed