The burp server is designed so that nearly all options can be changed without
requiring a reload or a restart.
It manages this by forking a child for each client that connects, and then
having the child process re-read the main server config file, before reading
the client-specific config file.
In a normal setup, the server config file will be /etc/burp/burp-server.conf,
and the client-specific config files will be in the /etc/burp/clientconfdir
Many global options set in the burp-server.conf can be overridden per-client
via the /etc/burp/clientconfdir files.