Restores nuclear power on Nulla when Cerys is installed.

With Nulla 1.0.2 and Cerys, placing a nuclear reactor on Nulla fails because the
ambient radiation is too high. Nulla reuses Cerys's radiation property to block
cryogenic plants, inadvertently activating Cerys's restrictions on other buildings
and recipes too.

This compatibility patch separates the two radiation properties:

• Nuclear reactors can be placed and crafted on Nulla.
• Labs, accumulators, boilers and heating towers no longer inherit Cerys's
  radiation restrictions on Nulla.
• Cryogenic plants remain blocked on Nulla.
• Cerys retains its existing radiation restrictions.
• Existing Nulla surfaces update automatically when the mod is added.
• New games and newly created Nulla surfaces are supported.

Install alongside Planet Nulla and
Cerys, restart Factorio and
load your save. No console commands or changes to either original mod are needed.

Requires Factorio 2.1 with Space Age. Tested using Factorio 2.1.24, Nulla
1.0.2, Cerys 4.25.0 and PlanetsLib 2.4.0, including actual player placement,
existing-save migration and save/reload checks.

This is an independent compatibility patch. Thanks to Cybranian (DimonSever000)
for Nulla, thesixthroc for Cerys, and the PlanetsLib authors.

License: MIT.