chore: prefer Docker Hub over Quay.io

charts/chronograf/Chart.yaml

 apiVersion: v1
 name: chronograf
-version: 1.1.1
+version: 1.1.2
 appVersion: 1.7.12
 description: Open-source web application written in Go and React.js that provides
   the tools to visualize your monitoring data and easily create alerting and automation

charts/chronograf/values.yaml

 ## Image Settings
 ##
 image:
-  repository: quay.io/influxdb/chronograf
+  repository: "chronograf"
   tag: 1.7.12
   pullPolicy: IfNotPresent