reparent.py: Fix style issue.

test/reparent.py

@@ -508,7 +508,7 @@ class TestReparent(unittest.TestCase):
     logging.debug('New master position: %s', str(new_pos))
     # Use "localhost" as hostname because Travis CI worker hostnames are too long for MySQL replication.
     changeMasterCmds = mysql_flavor().change_master_commands(
-                            "localhost",
+        'localhost',
         tablet_62044.mysql_port,
         new_pos)