Fix potential problems (StarGate)

[zimzaza4]

Changes

If the player's destination is not an alien world, don't give the player Metadata

Related Issues

hmm

Checklist

• [ ] I have fully tested the proposed changes and promise that they will not break world generation, mob spawning, and the like.
• [ ] I followed the existing code standards and didn't mess up the formatting.
• [ ] I did my best to add documentation to any public classes or methods I added.
• [ ] I have added Nonnull and Nullable annotations to my methods to indicate their behaviour for null values