Allow enter to select items from combobox's list (#7351)

src/gui/guiFormSpecMenu.cpp

@@ -2981,7 +2981,9 @@ bool GUIFormSpecMenu::preprocessEvent(const SEvent& event)
 			gui::IGUIElement *focused = Environment->getFocus();
 			if (focused && isMyChild(focused) &&
 					(focused->getType() == gui::EGUIET_LIST_BOX ||
-					 focused->getType() == gui::EGUIET_CHECK_BOX)) {
+					focused->getType() == gui::EGUIET_CHECK_BOX) &&
+					(focused->getParent()->getType() != gui::EGUIET_COMBO_BOX ||
+					event.KeyInput.Key != KEY_RETURN)) {
 				OnEvent(event);
 				return true;
 			}