Fix bug on y bitset extraction from 1.16 update

accidently copied z's to y.

seems to impact light only, but is not the source of the light bug we've been trying to fix

Spigot-Server-Patches/Optimize-Bit-Operations-by-inlining.patch

@@ -31,7 +31,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
      public static int c(long i) {
 -        return (int) (i << 64 - BlockPosition.h >> 64 - BlockPosition.h);
-+        return (int) ((i << 26) >> 38);  // Paper - simplify/inline
++        return (int) ((i << 52) >> 52); // Paper - simplify/inline
      }
  
      public static int d(long i) {