fixup! ERP5Workflow: DC Workflows are now ERP5 objects (!1378).

fix convertToERP5Workflow() for the case where permission_roles is not yet configured.

product/ERP5Type/patches/DCWorkflow.py

@@ -1024,9 +1024,13 @@ def convertToERP5Workflow(self, temp_object=False):
 
         acquire_permission_list = []
         permission_roles_dict = {}
-        if sdef.permission_roles:
-          for (permission, roles) in sdef.permission_roles.items():
-            if permission in self.permissions:
+        permission_roles = sdef.permission_roles or {}
+        for permission in self.permissions:
+          roles = permission_roles.get(permission, None)
+          if roles is None:
+            acquire_permission_list.append(permission)
+            permission_roles_dict[permission] = ()
+          else:
             if isinstance(roles, list): # type 'list' means acquisition
               acquire_permission_list.append(permission)
             permission_roles_dict[permission] = list(roles)