[1.6.x] Updated contrib.admin to use Email/URLInputs; refs #16630

Backport of 2a979d2a7b from master

tests/admin_widgets/models.py

@@ -13,6 +13,7 @@ class Member(models.Model):
     name = models.CharField(max_length=100)
     birthdate = models.DateTimeField(blank=True, null=True)
     gender = models.CharField(max_length=1, blank=True, choices=[('M','Male'), ('F', 'Female')])
+    email = models.EmailField(blank=True)
 
     def __str__(self):
         return self.name