HTTP panic when toggling spec.storage.tls.enabled to true, when using Tempo with AWS STS

[rubenvp8510]

When we set spec.storage.tls.enabled to true, using Tempo with AWS STS, we get the following error and the changes are not applied.

error: tempostacks.tempo.grafana.com "tmstack" could not be patched: Internal error occurred: failed calling webhook "vtempostack.tempo.grafana.com": failed to call webhook: Post "https://tempo-operator-controller-service.openshift-tempo-operator.svc:443/validate-tempo-grafana-com-v1alpha1-tempostack?timeout=10s": EOF
You can run `oc replace -f /var/folders/v_/xjhg70nn5h9g__sf8d7wg99r0000gn/T/oc-edit-307932674.yaml` to try this update again.

Steps to reproduce the issue:

• Install the Tempo operator on a STS enabled OCP cluster.
  

• Create a Tempo instance with AWS STS. 
  

• Set the spec.storage.tls.enabled to true in the TempoStack CR.
  

• The change will not be applied with the above errors in description.