Makes mines immune to explosive damage from enemies. Useful with mods like Explosive Biters.

Reasoning:

• Mines are buried, so surface explosions wouldn't realistically destroy them.
• This maintains the usefulness of mines when using mods that add explosive enemies.

Compatibility:

• No known incompatibilities or dependencies.
• Does not require Space Age.
• Mods that create new mine variants by copying the land-mine entity should inherit the change automatically.