kibana nodeSelector improperly indented

the Kibana CR's nodeSelector is improperly indented, which causes invalid helm rendering when providing kibana.nodeSelector.

Error: YAML parse error on logging/templates/kibana.yaml: error converting YAML to JSON: yaml: line 41: mapping values are not allowed in this context
helm.go:81: [debug] error converting YAML to JSON: yaml: line 41: mapping values are not allowed in this context