[Freeciv-Dev] Pollution with new techs

[Artur Biesiadowski <abies@xxxxxxxxx>]

Pollution modifier can be computed wrong in advdomestic.c:pollution_cost
and in cityturn.c:set_pollution. I think it should be
  mod = max(mod,i)
instead of
  mod = i
(in other case order of techs in ruleset is important).

Artur