* Previously, the nginx location would match on /foo/websocket... or
/foo/api/websocket... Now, we require these two paths to start at the
root i.e. <host>/websocket/... /api/websocket/...
* Note: We now also require an ending / and do NOT support
<host>/websocket_foobar but DO support <host>/websocket/foobar. This
was always the intended behavior. We want to keep
<host>/api/websocket/... "open" and routing to daphne in case we want
to add more websocket urls in the future.