Makes localname case insensitive

bookwyrm/models/user.py

@@ -4,6 +4,7 @@ from urllib.parse import urlparse
 
 from django.apps import apps
 from django.contrib.auth.models import AbstractUser, Group
+from django.contrib.postgres.fields import CICharField
 from django.core.validators import MinValueValidator
 from django.db import models
 from django.utils import timezone
@@ -54,7 +55,7 @@ class User(OrderedCollectionPageMixin, AbstractUser):
     summary = fields.HtmlField(null=True, blank=True)
     local = models.BooleanField(default=False)
     bookwyrm_user = fields.BooleanField(default=True)
-    localname = models.CharField(
+    localname = CICharField(
         max_length=255,
         null=True,
         unique=True,