AI: base_assess_defense_unit() hardcoded assumption about game.info.low_firepower_pearl_harbour
base_assess_defense_unit() does not use game.info.low_firepower_pearl_harbour, bad assumes UTYF_BADCITYDEFENDER firepower to be 1.
base_assess_defense_unit() does not use game.info.low_firepower_pearl_harbour, bad assumes UTYF_BADCITYDEFENDER firepower to be 1.