Fix external editor button updates

Make sure the pop-up button is updated in both multiple editors modes.

rtgui/editwindow.cc

@@ -488,6 +488,13 @@ void EditWindow::set_title_decorated(Glib::ustring fname)
     set_title("RawTherapee " + M("EDITWINDOW_TITLE") + subtitle);
 }
 
+void EditWindow::updateExternalEditorWidget(int selectedIndex, const std::vector<ExternalEditor> &editors)
+{
+    for (const auto& panel : epanels) {
+        panel.second->updateExternalEditorWidget(selectedIndex, editors);
+    }
+}
+
 void EditWindow::updateToolPanelToolLocations(
         const std::vector<Glib::ustring> &favorites, bool cloneFavoriteTools)
 {