fix passthrough of tenant_message
diff --git a/xos/tosca/resources/exampletenant.py b/xos/tosca/resources/exampletenant.py
index 608e75b..d9239f9 100644
--- a/xos/tosca/resources/exampletenant.py
+++ b/xos/tosca/resources/exampletenant.py
@@ -14,7 +14,7 @@
     provides = "tosca.nodes.ExampleTenant"
     xos_model = ExampleTenant
     name_field = "service_specific_id"
-    copyin_props = ("tenant_message")
+    copyin_props = ("tenant_message",)
 
     def get_xos_args(self, throw_exception=True):
         args = super(XOSExampleTenant, self).get_xos_args()