Freeciv

I introduced an error in one of my "string tweaks" (#689474), in 2017.

I changed the text for the "Multicultural" achievement in various rulesets from

• "In your nation there are citizens of 2 different nationalities!"

to

• "One of your cities has 2 different nationalities!"

But looking more closely at the code, the first version was correct -- achievement_check() counts total nationalities across all cities. And indeed I've seen this in a game after I first conquered a city.

As far as I can tell this is intentional; I find no evidence that anyone other than me was ever confused about this. (This achievement was added in gna patch #4161 .)

I'll correct this (it's just strings), and also state more explicitly in README.achievements what the criterion is.