Merge branch 'mk/http-backend-kill-children-before-exit'

The http-backend CGI process did not correctly clean up the child
processes it spawns to run upload-pack etc. when it dies itself,
which has been corrected.

* mk/http-backend-kill-children-before-exit:
http-backend: enable cleaning up forked upload/receive-pack on exit

diff --cc http-backend.c
Simple merge