Add maxlength to prevent truncation of endpoint URL

Closes #3462625

src/Plugin/WebformHandler/RestWebformHandler.php

@@ -104,6 +104,7 @@ class RestWebformHandler extends WebformHandlerBase {
     $form['remote']['endpoint'] = [
       '#title' => $this->t('Endpoint'),
       '#type' => 'textfield',
+      '#maxlength' => 255,
       '#default_value' => $this->configuration['endpoint'],
       '#description' => $this->t('Endpoint URL'),
       '#required' => TRUE,