Fail preset verification when ore spawnSize is less than 3

[sirati]

The following preset should generate a lot of netherrack and endstone everywhere.
https://pastebin.com/a5jmEg06

However it does not generate any.

[Niko-sk2x]

Works as intended, this is vanilla behavior for ore generation.

[sirati]

In that case you would need to fix the default worldgen template. @Barteks2x

Emerald has a spawnSize of 1 and thus wont generate in CWG

Also the verifier should reject any spawnSize so small that it wont spawn with an error to avoid debugging trouble for template makers.

Thus i request this to be reopened

[Niko-sk2x]

True, I should change the emerald generation.

Making it fail the verifier would break existing presets, but I may be able to drop ore entries with size < 3 in preset version upgrade for existing presets, and then enforce it in new versions.