fix: preference dialog crash, missing ref to ACTION_DROP_IDX

Author: nvandamme

ui/opensnitch/dialogs/preferences/dialog.py

@@ -147,7 +147,7 @@ def __init__(self, parent=None, appicon=None):
         self.helpButton.setIcon(helpIcon)
         self.dbFileButton.setIcon(openIcon)
 
-        self.comboUIAction.setItemIcon(Config.ACTION_DENY_IDX, denyIcon)
+        self.comboUIAction.setItemIcon(Config.ACTION_DROP_IDX, denyIcon)
         self.comboUIAction.setItemIcon(Config.ACTION_ALLOW_IDX, allowIcon)
         self.comboUIAction.setItemIcon(Config.ACTION_REJECT_IDX, rejectIcon)