fix(Tinebase): FIDO2 not working as areaLock device

tine20/Tinebase/js/MFA/Providers/WebAuthn.js

@@ -12,6 +12,7 @@ import Abstract from './Abstract'
 class WebAuthn extends Abstract {
     constructor (config) {
         super(config)
+        this.username = this.username || Tine.Tinebase.registry.get('currentAccount').accountLoginName
         // this.windowTitle = i18n._('MFA secret required')
         // this.questionText = formatMessage('This area is locked. To unlock it you need to provide the secret from your Multi factor authentication device {mfaDevice.device_name}.', this)
         // this.passwordFieldLabel = formatMessage('Secret from {mfaDevice.device_name}', this)