Fix template syntax (#9)

Actually fix chart template syntax for real this time.

Author: wafschneider

chart/templates/okapi-hook-job.yaml

@@ -32,8 +32,10 @@ spec:
             value: "{{ .Values.okapiUrl }}"
           - name: MODULE_URL
             value: "{{ .Values.moduleUrl }}"
+          {{- if .Values.tenants }}
           - name: OKAPI_TENANTS
-            value: "{{ join "," .Values.tenants | default [] }}"
+            value: "{{ join "," .Values.tenants }}"
+          {{- end }}
           - name: OKAPI_ADMIN_TENANT
             value: "{{ join "," .Values.supertenant }}"
           {{- range $k, $v := .Values.env }}