title: verbose_name_plural not working properly in django admin
body: <p>I am trying to change display for Model name in my django admin using <strong>verbose_name_plural</strong> in class Meta.</p>
  
  <p>here is my code :</p>
  
  <pre><code>class Country(models.Model):
      country_name = models.CharField(max_length=30)
      is_active = models.BooleanField(default=True)
      date_created = models.DateTimeField(auto_now_add=True)
      date_updated = models.DateTimeField(auto_now=True)
  
      def __str__(self):
          return self.country_name
  
      class Meta:
          verbose_name = "Country"
          verbose_name_plural = "Countries"
  </code></pre>
  
  <p>But it is not working, the display name is not changed in django admin list.</p>
  
  <p><a href="https://i.stack.imgur.com/YQGNI.png" rel="nofollow noreferrer">django-admin list models</a></p>
  
  <p>I also tried to :</p>
  
  <ul>
  <li>place the "Meta" class in admin.py -> not working</li>
  <li>already makemigrations &amp; migrate -> still same result</li>
  <li>stop and start server</li>
  </ul>
  
  <p>Thank you for any comment/advice. </p>