The prepare-workspace-git role recently replaced the use-cached-repos
role, but its behavior is slightly different. While use-cached-repos
removed the 'origin' remote, prepare-workspace-git replaces it with a
zuul fake origin.
Release jobs used to add an 'origin' remote to enable notes fetching.
Those jobs now fail because the 'origin' remote already exists. We
fix this by resetting the URL for the 'origin' remote, instead of
adding a new one.
Change-Id: Ifa80ff02dd06a65fd60189c97438554fc4100932
50c3fb9f59