Default WSGI config does not match mod_wsgi recommendation

The default Apache config file at `deployment/datapusher.conf` sets "WSGIDaemonProcess ... processes=1"; however, the `mod_wsgi` documentation at https://modwsgi.readthedocs.io/en/develop/user-guides/processes-and-threading.html#the-mod-wsgi-daemon-processes recommends that if you only want a single process, then you should not set the "processes" parameter at all.