Backport the following commit from Bitcoin Core
commit 1581ecbc33edd9d6257e50b11d8854fbccaf8ad8
Author: John Newbery <john@johnnewbery.com>
Date: Mon Jan 30 14:57:27 2017 -0800
Use configparser in rpc-tests.py
Remove the use of wildcard imports in rpc-tests.py and replace with
configparser.