Bug Seeds With Mineshafts

Summary:

This seed can causing feature to repeat mineshaft.

Step to reproduce:

1. Create the new world and using this seeds in the table:

   List of Seeds	Repetition direction
   -1171867832	Vertical
   1000686894	Vertical

1. Command: /locate mineshaft
2. Using tp command with mineshaft coordinates list
3. Break the block downwards to mineshaft

Observed Results:

This mineshaft has repeat vertically.

Expected Results:

This mineshaft should generates with random coordinates.