LibGUI: Don't search ComboBox Windows when holding a mod key

Author: https://github.com/thankyouverycool
Commit: https://github.com/SerenityOS/serenity/commit/4ba20f08c7
Pull-request: https://github.com/SerenityOS/serenity/pull/16098

Userland/Libraries/LibGUI/ComboBox.cpp

@@ -94,7 +94,7 @@ ComboBox::ComboBox()
     m_editor->on_keypress = [this](KeyEvent& event) {
         if (!m_only_allow_values_from_model)
             return;
-        if (!m_list_window->is_visible() && event.key() <= Key_Z && event.key() >= Key_A) {
+        if (!m_list_window->is_visible() && event.key() <= Key_Z && event.key() >= Key_A && event.modifiers() == Mod_None) {
             open();
             m_list_window->event(event);
         }