Login form will force username if there is an authenticated user

app/assets/app/auth/login/Form.component.js

@@ -75,6 +75,14 @@ export default class AuthLoginForm extends Component {
         this.button_text = 'Next'
     }
 
+    async vue_on_create() {
+        const auth_user = await auth_api.get_authenticated_user()
+        if ( auth_user ) {
+            this.username = auth_user
+            await this.step_click()
+        }
+    }
+
     async on_key_up(event) {
         if ( event.keyCode === 13 ) {
             // Enter was pressed