fix changing state of organic checkbox causing crash

app/activities/PriceCheck.py

@@ -149,7 +149,7 @@ class PriceCheck(FocusWidget):
             u"Organic",
             state='mixed',
         )
-        urwid.connect_signal(self.organic_checkbox, 'change', lambda w,v: self.apply_changes('organic', w, v))
+        urwid.connect_signal(self.organic_checkbox, 'change', lambda _,v: self.apply_changes('organic', v))
         
         fields = [f for f in fields ]
         for k in fields: