message: fix: Guard against null in client side logout function
diff: @@ -163,7 +163,7 @@ export class AuthenticationClient {
  }
  logout () {
  - return this.app.get('authentication')
  + return Promise.resolve(this.app.get('authentication'))
  .then(() => this.service.remove(null))
  .then((authResult: AuthenticationResult) => this.removeAccessToken()
  .then(() => this.reset())
  