bpo-37531: regrtest main process uses shorter timeout (GH-16220) (GH-16224)

When using multiprocesss (-jN), the main process now uses a timeout
of 60 seconds instead of the double of the --timeout value. The
buildbot server stops a job which does not produce any output in 1200
seconds.
(cherry picked from commit 46b0b81220a23bc4aee5ba3ba67e8cf1b5df7960)

Co-authored-by: Victor Stinner <vstinner@redhat.com>
1 file changed