title: Default value for models.GenericIpAddressField
body: <p>i am trying to add another column in my model:</p>
  
  <blockquote>
    <p>ip_address = models.GenericIPAddressField()</p>
  </blockquote>
  
  <p>and when i run makemigrations, i have to set a default value. what should i put? thanks in advance.</p>
  
  <p><strong>models.py</strong></p>
  
  <pre><code>class Prospect(models.Model):
      full_name = models.CharField(max_length=120)
      email = models.CharField(max_length=80)
      contact_number = models.CharField(max_length=14)
      timestamp = models.DateTimeField(auto_now_add=True, auto_now=False)
      user = models.ForeignKey(VendicsUser, null=True)
      ip_address = models.GenericIPAddressField()
  
      def __unicode__(self):
          return self.full_name
  
      def __str__(self):
          return self.email
  </code></pre>