fix: do not raise if user_data is not present

src/rougail/cli/__main__.py

@@ -20,7 +20,7 @@ from tiramisu_cmdline_parser import TiramisuCmdlineParser
 from tiramisu import Config
 from pathlib import Path
 
-from rougail import Rougail
+from rougail import Rougail, PropertiesOptionError
 from rougail.config import get_rougail_config
 from rougail.update import RougailUpgrade
 from rougail.utils import load_modules
@@ -46,7 +46,10 @@ def _main():
     if rougailconfig["upgrade"]:
         RougailUpgrade(rougailconfig=rougailconfig).run()
         return
+    try:
         user_data_names = rougailconfig["step.user_data"]
+    except PropertiesOptionError:
+        user_data_names = []
     output_name = rougailconfig["step.output"]
     # structural
     rougail = Rougail(rougailconfig)