Fix oauth urls

`user/auth` doesn't work, gives 404.
Had to replace by `sign-in/oauth`

frontend/modules/user/views/sign-in/login.php

@@ -44,7 +44,7 @@
                     <h4 class="text-muted text-center"><?php echo Yii::t('frontend', 'Log in with')  ?></h4>
 
                     <?php $authAuthChoice = yii\authclient\widgets\AuthChoice::begin([
-                        'baseAuthUrl' => ['site/auth']
+                        'baseAuthUrl' => ['sign-in/oauth']
                     ]); ?>
                     <ul class="list-inline d-flex justify-content-center">
                         <?php foreach ($authAuthChoice->getClients() as $client) : ?>
@@ -57,4 +57,4 @@
         </div>
     </div>
 </div>
-<?php ActiveForm::end(); ?>
+<?php ActiveForm::end(); ?>