Check for allowed namespaces when providing a clusterrole

Found an issue where, when providing your own clusterRole, flux is not
able to provision in namespaces other than it's own. The work around is
to add all namespaces to the allowedNamespaces value but this change
will not add that option if a clusterRole name has been provided

* Add second condition for adding allowed namspeaces

Signed-off-by: David Curran <david.curran@health.telstra.com>
Signed-off-by: Kingdon Barrett <kingdon@weave.works>

chart/flux/templates/deployment.yaml

@@ -195,7 +195,7 @@ spec:
               name: {{ .Values.env.secretName }}
           {{- end }}
           args:
-          {{- if not .Values.clusterRole.create }}
+          {{- if and (not .Values.clusterRole.create) ( .Values.allowedNamespaces) }}
           - --k8s-allow-namespace={{ join "," (append .Values.allowedNamespaces .Release.Namespace) }}
           {{- end}}
           {{- if .Values.defaultNamespace }}