don't list directory contents of something that is empty

verse/distribusiworkflow.py

@@ -92,6 +92,7 @@ def RemoveMacFolders(path):
 def GetCssFile(distribusi):
     cssfile = ""
     cssfolder = os.path.join("themes/userthemes", distribusi.distribusiname)
+    if os.path.exists(cssfolder):
         for filename in os.listdir(cssfolder):
             if filename.endswith(".css"):
                 cssfile = os.path.join(cssfolder, filename)