Granularity: Set 'unit.cultivate' as alt activity gfx for irrigation
Granularity ruleset irrigation extra does not have fallback activity gfx tag to "unit.cultivate" for tilesets that do not have the extra specific sprite. Add the fallback.
Granularity ruleset irrigation extra does not have fallback activity gfx tag to "unit.cultivate" for tilesets that do not have the extra specific sprite. Add the fallback.