cluster.certificates should be of type 'object' on values schema

[carlosrmendes]

Setting serverTLSSecret and replicationTLSSecret on .cluster.certificates leads to this error upon helm install:

Error: values don't meet the specifications of the schema(s) in the following chart(s):
cluster:
- cluster.certificates: Invalid type. Expected: null, given: object

helm.go:84: [debug] values don't meet the specifications of the schema(s) in the following chart(s):
cluster:
- cluster.certificates: Invalid type. Expected: null, given: object