Issue #2294313 by Ieva Uzule, rachel_norfolk, nathanlawson91, xadag,...

Issue #2294313 by Ieva Uzule, rachel_norfolk, nathanlawson91, xadag, er.pushpinderrana, Dominique CLAUSE, marcus7777: Email is asked before user name in SiteConfigureForm.

core/lib/Drupal/Core/Installer/Form/SiteConfigureForm.php

@@ -147,12 +147,6 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#type' => 'fieldgroup',
       '#title' => $this->t('Site maintenance account'),
     );
-    $form['admin_account']['account']['#tree'] = TRUE;
-    $form['admin_account']['account']['mail'] = array(
-      '#type' => 'email',
-      '#title' => $this->t('Email address'),
-      '#required' => TRUE,
-    );
     $form['admin_account']['account']['name'] = array(
       '#type' => 'textfield',
       '#title' => $this->t('Username'),
@@ -166,6 +160,12 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#required' => TRUE,
       '#size' => 25,
     );
+    $form['admin_account']['account']['#tree'] = TRUE;
+    $form['admin_account']['account']['mail'] = array(
+      '#type' => 'email',
+      '#title' => $this->t('Email address'),
+      '#required' => TRUE,
+    );
 
     $form['regional_settings'] = array(
       '#type' => 'fieldgroup',