Merge branch 'rj/receive-pack-avoid-sigpipe-during-status-reporting'

Merge branch 'rj/receive-pack-avoid-sigpipe-during-status-reporting'

When the "git push" command is killed while the receiving end is
trying to report what happened to the ref update proposals, the
latter used to die, due to SIGPIPE.  The code now ignores SIGPIPE
to increase our chances to run the post-receive hook after it
happens.

* rj/receive-pack-avoid-sigpipe-during-status-reporting:
  receive-pack: ignore SIGPIPE while reporting status to client