don't uninstall oslo.config

There is a totally crazy sequencing issue that happens by uninstall
oslo.config here, don't do it. It's an incredibly old work around from
before we installed oslo.config as a non editable install.

Change-Id: Ic2364681e51e82e0d7b374728c177a47e04cbd1b
(cherry picked from commit 010a882dad6aba9b5b135c8fd207c3237a1436c4)