Remove unused OneToOneField in DatabaseWrapper.data_types

Relational fields use the db_type of the related field.

Author: timgraham

django_mongodb_backend/base.py

@@ -50,7 +50,6 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         "BigIntegerField": "long",
         "GenericIPAddressField": "string",
         "JSONField": "object",
-        "OneToOneField": "int",
         "PositiveBigIntegerField": "int",
         "PositiveIntegerField": "long",
         "PositiveSmallIntegerField": "int",