Fix PY3 hasattr connecting to the db at define time

mongoengine/base/metaclasses.py

@@ -340,7 +340,7 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
             new_class._meta['collection'] = collection(new_class)
 
         # Provide a default queryset unless exists or one has been set
-        if not hasattr(new_class, 'objects'):
+        if 'objects' not in dir(new_class):
             new_class.objects = QuerySetManager()
 
         # Validate the fields and set primary key if needed

tests/document/instance.py

@@ -1857,6 +1857,8 @@ class InstanceTest(unittest.TestCase):
     def test_db_alias_propagates(self):
         """db_alias propagates?
         """
+        register_connection('testdb-1', 'mongoenginetest2')
+
         class A(Document):
             name = StringField()
             meta = {"db_alias": "testdb-1", "allow_inheritance": True}