text: Title: Submit button of login page should not use `id="submit"`
  Body: The 57th line of the file `/core/templates/login.php` have a potential bug
  ```
  <input type="submit" id="submit" class="login primary" title="" value="<?php p($l->t('Log in')); ?>" disabled="disabled" />
  ```
  When I run the code `document.querySelector('form[name="login"]').submit()` under login page and an error will be thrown
  ```
  VM78:1 Uncaught TypeError: document.querySelector(...).submit is not a function
      at <anonymous>:1:46
  ```
  I can't submit this form because `document.querySelector('form[name="login"]').submit` is not a function but a HTMLElement of the submit button.
  
  Please fix it and thanks!
  
  Version Of Server: v13.0.4 and v14