Relative URL in index.yaml

[ben-arnold-dbs]

Hi there,
I'm refering to fluxcd/charts#2

It would be awesome to pull fluxcd trough an artifactory mirror. To archive this, the urls in the index.yaml need to be relative.
This is possible since Helm v2.8.0.

I think, all it needs is to replace helm repo index . --url ${CHARTS_URL} with helm repo index . --url ${REPOSITORY} in Line 87 of the entrypoint.sh.