Skip test_conc279 when running with MaxScale

(see https://jira.mariadb.org/browse/MXS-4961)

testing/test/integration/test_nondbapi.py

@@ -133,6 +133,8 @@ class CursorTest(unittest.TestCase):
         del cursor
 
     def test_conpy279(self):
+        if is_maxscale():
+            self.skipTest("MAXSCALE bug MXS-4961")
         conn = self.connection
         default_conf = conf()
         if "password" not in default_conf: