AI siege bug with elephants

The AI will attempt to capture a city with only elephants as its siege weapon. After the AI forces combat, it just sits there and does nothing. You can speed up time and let the battle run for hours and it will not attempt to break down the walls with its elephants.

That's never going to be fixed, it's a hardcoded state triggered by the presence of elephants of course.
Leftover from RTW and due to the gates being coded differently, triggers that problem.