Revert expected failure test marked as a success test.

Author: WaVEV

django_mongodb/features.py

@@ -77,6 +77,8 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         # QuerySet.extra(where=...) should raise NotSupportedError instead of:
         # 'ExtraWhere' object has no attribute 'as_mql'.
         "many_to_one.tests.ManyToOneTests.test_selects",
+        # Incorrect JOIN with GenericRelation gives incorrect results.
+        "generic_relations_regress.tests.GenericRelationTests.test_annotate",
         # subclasses of BaseDatabaseWrapper may require an is_usable() method
         "backends.tests.BackendTestCase.test_is_usable_after_database_disconnects",
         # Connection creation doesn't follow the usual Django API.