Make utils.dict_to_querystring result predictible
Make utils.dict_to_querystring result predictible

The generated string of method doesn't always returns the
same result, this change fixes that.

Change-Id: I75666fc6c766bfcd80186ceac2c88134d6c8d899

gnocchixyz/python-gnocchiclient,sileht/python-gnocchiclient,gnocchixyz/python-gnocchiclient