[stable/prometheus] Switch from localhost to 127.0.0.1 (#6788)

* Switch from localhost to 127.0.0.1

The container is a binary only container without `/etc/hosts` or `/etc/resolv.conf` which will hit the dns server to resolv `localhost -> 127.0.0.1`

We had the case that there was a VM named `localhost` in the cloud and when hitting the DNS to resolv `localhost` we got the IP from this vm instead of `127.0.0.1`.

Took hours to find this issue :(

* Update prometheus chart version

* Bump version to 7.0.0

stable/prometheus/Chart.yaml

@@ -1,5 +1,5 @@
 name: prometheus
-version: 6.10.0
+version: 7.0.0
 appVersion: 2.3.2
 description: Prometheus is a monitoring system and time series database.
 home: https://prometheus.io/

stable/prometheus/templates/server-deployment.yaml

@@ -56,7 +56,7 @@ spec:
           imagePullPolicy: "{{ .Values.configmapReload.image.pullPolicy }}"
           args:
             - --volume-dir=/etc/config
-            - --webhook-url=http://localhost:9090{{ .Values.server.prefixURL }}/-/reload
+            - --webhook-url=http://127.0.0.1:9090{{ .Values.server.prefixURL }}/-/reload
           {{- range $key, $value := .Values.configmapReload.extraArgs }}
             - --{{ $key }}={{ $value }}
           {{- end }}