fix up missing space in url element of helm chart

The Chart.yaml.tpl was missing a space after the `url:` element for
maintainer team, resulting in the following error when eventually
running the scripts/helm-publish-chart.sh script:

```
Generating Helm chart package for mq@v0.0.2 ... Error: cannot load Chart.yaml: error converting YAML to JSON: yaml: line 15: could not find expected ':'
```

Author: jaypipes

templates/helm/Chart.yaml.tpl

@@ -11,8 +11,8 @@ maintainers:
   - name: ACK Admins
     url: https://github.com/orgs/aws-controllers-k8s/teams/ack-admin
   - name: {{ .ServiceIDClean }} Admins
-    url:https://github.com/orgs/aws-controllers-k8s/teams/{{ .ServiceIDClean }}-maintainer
+    url: https://github.com/orgs/aws-controllers-k8s/teams/{{ .ServiceIDClean }}-maintainer
 keywords:
   - aws
   - kubernetes
-  - {{ .ServiceIDClean }}
+  - {{ .ServiceIDClean }}