update chronograf to 1.7.7-alpine (#10938)

stable/chronograf/Chart.yaml

 name: chronograf
-version: 1.0.0
-appVersion: 1.7
+version: 1.0.1
+appVersion: 1.7.7
 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
   rules.

stable/chronograf/README.md

@@ -43,7 +43,7 @@ The command removes all the Kubernetes components associated with the chart and
 
 ## Configuration
 
-The configurable parameters of the Chronograf chart and 
+The configurable parameters of the Chronograf chart and
 their descriptions can be seen in `values.yaml`. The [full image documentation](https://quay.io/influxdb/chronograf) contains more information about running Chronograf in docker.
 
 Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example,

stable/chronograf/values.yaml

@@ -2,7 +2,7 @@
 ##
 image:
   repository: "docker.io/chronograf"
-  tag: "1.7-alpine"
+  tag: "1.7.7-alpine"
   pullPolicy: "Always"
 
 ## Specify a service type