Fertility natural increase occurs on farms before construction

Issue description

See title. BTW, it also fills with water.

Expected behavior

This not to happen, as it isn't built yet.

Alternatively, to start at 100%, I mean, why would the soil be at 80%?

Reproduction steps

Place a farm in planning mode, wait. It will get up to 99.90% fertility eventually.

Game version

0.4.11

I cannot reproduce, I can see here that fertility is updated only for farms that got built. Maybe we fixed that independently.