Fix a typo in contributor docs
Fix a typo in contributor docs

This just makes a trivial typo fix in the minor-code-changes doc.

Change-Id: If0093316c393b09ed4d936d2625b2d27024bfdbc
Co-Authored-By: Abhishek Kekane <347f023312da2612574b9ae83478e5b88d6254e4@redhat.com>

openstack/glance,openstack/glance,openstack/glance