Helm chart 2.14.0 error if dashboard enabled after commonLabels added

[pippitt]

Which component:
controller helm chart

Describe the bug
Withmetrics.dashboards.create: true
helm generates an error

$ helm template testing . --values ./dashboard.values.yaml
Error: template: sealed-secrets/templates/configmap-dashboards.yaml:14:18: executing "sealed-secrets/templates/configmap-dashboards.yaml" at <.Values.commonLabels>: can't evaluate field Values in type []uint8

Use --debug flag to render out invalid YAML

To Reproduce
Steps to reproduce the behavior:

1. Set metrics.dashboards.create: true in values.yaml being used
2. Run helm command
3. See error listed above

Expected behavior
Helm produces objects without error.

Version of Kubernetes:
NA

I believe I have the fix, and will make a PR.