Added http_client_proxy setting field into Apigee edge administration configuration (#475)

Author: ngonendi

src/Form/ConnectionConfigForm.php

@@ -67,6 +67,14 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#required' => TRUE,
     ];
 
+     $form['http_proxy'] = [
+           '#type' => 'textfield',
+           '#title' => $this->t('HTTP client proxy'),
+           '#description' => $this->t('The Http proxy used to connect to Apigee Edge.'),
+           '#default_value' => $this->config('apigee_edge.client')->get('http_client_proxy'),
+           '#required' => FALSE,
+     ];
+
     return parent::buildForm($form, $form_state);
   }
 
@@ -77,6 +85,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     $this->config('apigee_edge.client')
       ->set('http_client_connect_timeout', $form_state->getValue('connect_timeout'))
       ->set('http_client_timeout', $form_state->getValue('request_timeout'))
+      ->set('http_client_proxy', $form_state->getValue('http_proxy'))
       ->save();
     parent::submitForm($form, $form_state);
   }