Add server.address property and update issuer field in LoginController to use dynamic server address. Modify SQL query in PrivilegedUserMapper to simplify permissions retrieval.

backend/src/main/resources/application-beta.properties

@@ -5,4 +5,5 @@ database.host=${DB_HOST:localhost}
 database.user=${DB_USER:root}
 database.password=${DB_PASSWORD:root}
 cors.allowed-origins=${CORS:https://beta.alttd.com}
+server.address=${SERVER_ADDRESS:https://beta.alttd.com}
 logging.level.com.alttd.altitudeweb=DEBUG