Remove old test code

Author: rpkilby

tests/test_jsonfield.py

@@ -2,7 +2,6 @@
 from collections import OrderedDict
 from decimal import Decimal
 
-import django
 from django.core.serializers import deserialize, serialize
 from django.core.serializers.base import DeserializationError
 from django.forms import ValidationError
@@ -195,12 +194,7 @@ def test_invalid_json(self):
             '"fields": {"json": "{]", "default_json": "{]"}}]'
         with self.assertRaises(DeserializationError) as cm:
             next(deserialize('json', ser))
-        # Django 2 does not reraise DeserializationError as another DeserializationError
-        # Changed in: https://github.com/django/django/pull/7878
-        if django.VERSION < (2, 0,):
-            inner = cm.exception.__context__.__context__
-        else:
-            inner = cm.exception.__context__
+        inner = cm.exception.__context__
         self.assertIsInstance(inner, ValidationError)
         self.assertEqual('Enter valid JSON.', inner.messages[0])