Fix incorrect nesting of liveness and readiness probes

[jpflouret]

Liveness and readiness probes introduced in #117 are incorrectly nested within the resources template. Adding resource limits to the pms chart results in the following error:

Error: template: plex-media-server/templates/statefulset.yaml:123:28: executing "plex-media-server/templates/statefulset.yaml" at <.Values.pms.livenessProbe>: nil pointer evaluating interface {}.pms

This change fixes that issue.

[jpflouret]

I believe the checks are failing due to the fact that the liveness and readiness probes are by default empty which is not valid.

        livenessProbe:
          {}
        readinessProbe:
          {}

I think this error didn't materialize itself in the previous PR due to it being hidden by the resources error that this PR fixes.

[jpflouret]

@MarshallAsch I think your commit is unsigned. Do you want me to redo the chart bump change and sign it myself?

[MarshallAsch]

no thats okay. I havent fixed my signing key so my commits are all unsigned now (I can bypass that requirement)