Enable token request for HostingSignupDialog

Needed for the last part of setup which is triggering
a migration process to the new host.

src/components/views/dialogs/HostingSignupDialog.tsx

@@ -49,6 +49,9 @@ export default class HostingSignupDialog extends React.PureComponent<IProps, ISt
         }
 
         switch (message.data.action) {
+            case 'access_token_credential_request':
+                this.sendAccessToken();
+                break;
             case 'openid_credentials_request':
                 // noinspection JSIgnoredPromiseFromCall
                 this.fetchOpenIDToken();
@@ -100,6 +103,13 @@ export default class HostingSignupDialog extends React.PureComponent<IProps, ISt
         }
     }
 
+    private sendAccessToken() {
+        this.sendMessage({
+            action: 'access_token_credential',
+            token: MatrixClientPeg.get().getAccessToken(),
+        });
+    }
+
     public componentDidMount() {
         window.addEventListener("message", this.messageHandler);
     }