process_fts_updates: Nagios may lack permissions to load Django config.
process_fts_updates: Nagios may lack permissions to load Django config.

Even if Django and PostgreSQL are on the same host, the `nagios` user
may lack permissions to read accessory configuration files needed to
load the Django configuration (e.g. authentication keys).

Catch those failures, and switch to loading the required settings from
`/etc/zulip/zulip.conf`.

rht/zulip,rht/zulip,rht/zulip,rht/zulip,zulip/zulip,zulip/zulip,rht/zulip,rht/zulip,zulip/zulip,zulip/zulip,andersk/zulip,rht/zulip,andersk/zulip,andersk/zulip,zulip/zulip,andersk/zulip,zulip/zulip,andersk/zulip,andersk/zulip,zulip/zulip,andersk/zulip