networking: self.model is always undefined

Stop using `self.model` which is undefined. Instead use the `model`
constant defined at the top of `NetworkInterfacePage`.

This previously was not a problem because the `model` is only needed
when a new connection needs to be created and the autoconnect toggle
never used to do that. With non-persistent `Wired Connection`
being treated differently the model is now required when toggling
autoconnect as new connection is created.

Author: tomasmatus

pkg/networkmanager/network-interface.jsx

@@ -306,7 +306,7 @@ export const NetworkInterfacePage = ({
                             <Checkbox id="autoreconnect" isDisabled={!privileged}
                                       onChange={(_event, checked) => {
                                           settings.connection.autoconnect = checked;
-                                          settings_applier(self.model, dev, con)(settings);
+                                          settings_applier(model, dev, con)(settings);
                                       }}
                                       isChecked={settings.connection.autoconnect}
                                       label={_("Connect automatically")} />