Update uwsgi settings for clean shutdown

The default uwsgi config doesn't play well with consul-template. Add
exit-on-reload for clean shutdown. The rest of changes help make startup
more robust.

docker/uwsgi/uwsgi.ini

@@ -1,4 +1,6 @@
 [uwsgi]
+uid = www-data
+gid = www-data
 master = true
 socket = 0.0.0.0:13032
 module = manage
@@ -9,3 +11,7 @@ processes = 20
 disable-logging = true
 ; increase buffer size for requests that send a lot of mbids in query params
 buffer-size = 8192
+; when uwsgi gets a sighup, quit completely and let runit restart us
+exit-on-reload = true
+need-app = true
+log-x-forwarded-for=true