Fix auth.disable_login_form in the example in README.md
When we test the example of the README, it fails :
$ kubectl apply -f grafana.yaml The Grafana "grafana" is invalid: spec.config.auth.disable_login_form: Invalid value: "boolean": spec.config.auth.disable_login_form in body must be of type string: "boolean"
CHANGELOG:
When we test the example of the README, it fails :
$ kubectl apply -f grafana.yaml The Grafana "grafana" is invalid: spec.config.auth.disable_login_form: Invalid value: "boolean": spec.config.auth.disable_login_form in body must be of type string: "boolean"