URLs can be more friendly to self-hosted users

[mgeerling]

Within the constants file:

// **** ROS On-Premises Users
// **** Replace the AUTH_URL string with the fully qualified address of your ROS server, e.g.:
// **** "http://127.0.0.1:9080" and "realm://127.0.0.1:9080"

Should really read:

// **** ROS On-Premises Users
// **** Replace the MY_INSTANCE_ADDRESS string with the fully qualified address of your ROS server, e.g.:
// **** "http://127.0.0.1:9080"