[stable/kong] quote host for proxy ingress (#19785)

To enable specification of wildcard hosts we need to ensure that the
host is quoted, otherwise we need to explicitly quote hosts of the form
`*.somedomain.tld`. Before this change, for something of the form `helm
install stable/kong kong --set-string='*.somedomain.tld'` we would
produce:

```
$ helm template ... --set-string='*.somedomain.tld'
...
    - host: *.somedomain.tld
...
```

which results in something of the form "error converting YAML to JSON:
yaml: line 17: did not find expected alphabetic or numeric character".
With the quoting we end up with:

```
$ helm template ... --set-string='*.somedomain.tld'
...
    - host: '*.somedomain.tld'
...
```

Some resources that I happened upon that provide some prior art and the
above solution:

 1. https://github.com/helm/helm/issues/5080
 2. https://github.com/jupyterhub/zero-to-jupyterhub-k8s/issues/1058

Signed-off-by: Harry Waye <harry@arachnys.com>

stable/kong/Chart.yaml

@@ -12,5 +12,5 @@ maintainers:
 name: kong
 sources:
 - https://github.com/Kong/kong
-version: 0.31.0
+version: 0.31.1
 appVersion: 1.4

stable/kong/templates/ingress-proxy.yaml

@@ -27,7 +27,7 @@ spec:
               servicePort: {{ $servicePort }}
     {{ else -}}
     {{- range $host := .Values.proxy.ingress.hosts }}
-    - host: {{ $host }}
+    - host: {{ $host | quote }}
       http:
         paths:
           - path: {{ $path }}