Updating project.conf with a new url does not cause an update of the ostree config

I initially changed the contents of buildstream.conf to update the push url to 1.2.3.4 from 4.3.2.1, however, I forgot to update the contents of the project.conf. Resulting in the config of my ostree cache looking like:

~/.cache/buildstream/artifacts/ostree$ cat config
[core]
repo_version=1
mode=bare-user

[remote "ssh___push_1_2_3_4_artifacts_"]
url=http://4.3.2.1/artifacts/
gpg-verify=false

however, after updating my project.conf with:

artifacts:
  url: http://1.2.3.4/artifacts/

the ostree config did not update the url of the remote.

@samthursfield Took a quick look and pointed out https://github.com/ostreedev/ostree/blob/master/src/libostree/ostree-repo.h#L201, essentially, if a remote exists with that name, it won't do anything.