Fix check if server.ha.replicas is a number when set in values.yaml

[wtfloris]

The commits merged in #943 only work when using --set 'server.ha.replicas=2' from the CLI, not when server.ha.replicas is defined in values.yaml. This behaviour is expected and described in helm/helm#12084. You can see this in action on this playground.

This passes the unit tests because they don't use values.yaml, so only the CLI behaviour is tested and this passed without raising issues.

By checking if the value is either int64 or float64, both cases work. There are no other cases where a value is checked if it's int64, so this should not occur anywhere else in this chart.

[hashicorp-cla]

Thank you for your submission! We require that all contributors sign our Contributor License Agreement ("CLA") before we can accept the contribution. Read and sign the agreement

Learn more about why HashiCorp requires a CLA and what the CLA includes

---

Floris Heringa seems not to be a GitHub user.
You need a GitHub account to be able to sign the CLA. If you already have a GitHub account, please add the email address used for this commit to your account.

_{Have you signed the CLA already but the status is still pending? Recheck it.}