The default is 50, which we believe was causing too much CPU
contention in prod during restarts. This commit lowers the max to 20.
The django-command-line script needs to be restarted manually to pick
up this change.
(imported from commit c2d097d2141be50b6222efb4a34142108c241cce)
This meant that (in some circumstances, anyway) the script would bail after the
inner process was killed by restart-server.
Manual deployment steps:
After pushing, log into {staging,app} and restart these commands within
the screen session.
(imported from commit 696bc8148fa9df4b536253d54c65b7c4cb908530)
