fix: gracefully shutdown Kong on service stop

`kong quit` is already used within `start-kong.sh` for the all-in-one image. The sole purpose of `start-kong.sh` is to trap exit to run `kong quit`, perhaps `stopsignal=QUIT` in the supervisord config would be equivalent, but it ain't broke.

Author: thebengeu

ansible/files/kong_config/kong.service.j2

@@ -8,16 +8,16 @@ Conflicts=envoy.service
 Type=forking
 ExecStart=/usr/local/bin/kong start -c /etc/kong/kong.conf
 ExecReload=/usr/local/bin/kong reload -c /etc/kong/kong.conf
-ExecStop=/usr/local/bin/kong stop
+ExecStop=/usr/local/bin/kong quit
 User=kong
 EnvironmentFile=/etc/kong/kong.env
 Slice=services.slice
 Restart=always
 RestartSec=3
 LimitNOFILE=100000
 
-# The kong user is unpriviledged and thus not permited to bind on ports < 1024
-# Via systemd we grant the process a set of priviledges to bind to 80/443
+# The kong user is unprivileged and thus not permitted to bind on ports < 1024
+# Via systemd we grant the process a set of privileges to bind to 80/443
 # See http://archive.vn/36zJU
 AmbientCapabilities=CAP_NET_BIND_SERVICE