Don't impose uniqueness on the subnets of the allocation log

coin/resources/models.py

@@ -131,7 +131,7 @@ class IPAllocationLog(models.Model):
     """
     # All we need to do is automatically fill this in upon other objects'
     # creation/destruction/deactivation.
-    subnet = CidrAddressField(unique=True)
+    subnet = CidrAddressField()
     user = models.ForeignKey('members.Member', null=True, blank=True,
                              on_delete=models.SET_NULL)
     subscription = models.ForeignKey('offers.OfferSubscription', null=True,