Update scripts.py

fixes bug #464, which happens when controls is None, which leads to args_to being None.

modules/scripts.py

@@ -92,6 +92,7 @@ class ScriptRunner:
 
         for script in self.scripts:
             script.args_from = len(inputs)
+            script.args_to = len(inputs)
 
             controls = wrap_call(script.ui, script.filename, "ui", is_img2img)