Pocketmine-mp: Non-burning furnaces glow in the dark

[dktapps]

Issue description

Unlit furnaces emit block light. 🤦‍♂️

Expected result: What were you expecting to happen?

• Unlit furnaces I place to not glow in the dark

Actual result: What actually happened?

• furnace glows in the dark

Steps to reproduce the issue

1. set world to night time
2. place an unlit furnace
3. quit + rejoin, notice the area around the furnace is illuminated

OS and versions

• PocketMine-MP: 202bac28fc7f9332e5b02643d54d574a7fbe6732 with lots of local changes
• PHP: 7.0.17
• Server OS: w10
• Game version: PE

[dktapps]

Fixed on api3/network, will be closed automatically when the branch is merged.

[TheDiamondYT1]

It would make more sense for BurningFurnace to extend Furnace, not the other way around.