prevent joypad button input dropdown going out of dialog

(cherry picked from commit e47d5691e41eba5fab82ad4eb32223e58f186981)

editor/project_settings_editor.cpp

@@ -1999,6 +1999,8 @@ ProjectSettingsEditor::ProjectSettingsEditor(EditorData *p_data) {
 	device_index_label = l;
 
 	device_index = memnew(OptionButton);
+	device_index->set_clip_text(true);
+
 	vbc_right->add_child(device_index);
 
 	setting = false;