Remove extra check for auto_encryption_opts

Already would have failed on line 470

  File "/Users/alex.clark/Developer/django-mongodb-cli/src/django-mongodb-backend/django_mongodb_backend/schema.py", line 470, in _create_collection
    raise ImproperlyConfigured(
django.core.exceptions.ImproperlyConfigured: Encrypted fields found but DATABASES['encrypted']['OPTIONS'] is missing auto_encryption_opts.

Author: aclark4life

django_mongodb_backend/schema.py

@@ -502,12 +502,10 @@ def _get_encrypted_fields(
         path_prefix = path_prefix or ""
 
         options = client._options
-        auto_encryption_opts = getattr(options, "auto_encryption_opts", None)
+        auto_encryption_opts = options.auto_encryption_opts
 
-        key_vault_collection = None
-        if auto_encryption_opts:
-            key_vault_db, key_vault_coll = auto_encryption_opts._key_vault_namespace.split(".", 1)
-            key_vault_collection = client[key_vault_db][key_vault_coll]
+        key_vault_db, key_vault_coll = auto_encryption_opts._key_vault_namespace.split(".", 1)
+        key_vault_collection = client[key_vault_db][key_vault_coll]
 
         kms_provider = router.kms_provider(model)
         master_key = connection.settings_dict.get("KMS_CREDENTIALS", {}).get(kms_provider)