Debug world still sets clear weather time instead of deactivating gamerule doWeatherCycle

The bug

When debug worlds are setup a large clear weather value is set instead of setting the gamerule doWeatherCycle to false.

How to reproduce

1. Create a debug world (hold Alt while clicking at the world types)
2. Check the value of the gamerule doWeatherCycle

   /gamerule doWeatherCycle
   

Code analysis

Based on 1.12.2 decompiled using MCP 9.40

See method net.minecraft.world.WorldServer.setDebugWorldSettings().