Fix coding standard violations

$ phpcs --standard=Drupal DiscordAuthManager.php

FILE: ...rs\Navyaa\Desktop\social_auth_discord\src\DiscordAuthManager.php
----------------------------------------------------------------------
FOUND 1 ERROR AFFECTING 1 LINE
----------------------------------------------------------------------
 1 | ERROR | [x] End of line character is invalid; expected "\n" but
   |       |     found "\r\n"
----------------------------------------------------------------------
PHPCBF CAN FIX THE 1 MARKED SNIFF VIOLATIONS AUTOMATICALLY
----------------------------------------------------------------------

$ phpcs --standard=DrupalPractice .

FILE: ...rs\Navyaa\Desktop\social_auth_discord\src\DiscordAuthManager.php
----------------------------------------------------------------------
FOUND 1 ERROR AFFECTING 1 LINE
----------------------------------------------------------------------
 113 | ERROR | The $_GET super global must not be accessed directly;
     |       | inject the request.stack service and use
     |       | $stack->getCurrentRequest()->query->get('code')
     |       | instead
----------------------------------------------------------------------


FILE: ...Desktop\social_auth_discord\src\Form\DiscordAuthSettingsForm.php
----------------------------------------------------------------------
FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
----------------------------------------------------------------------
 145 | WARNING | t() calls should be avoided in classes, use
     |         | \Drupal\Core\StringTranslation\StringTranslationTrait
     |         | and $this->t() instead
----------------------------------------------------------------------

Time: 142ms; Memory: 6MB