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/0504-Optimize-Bit-Operations-by-inlining.patch

@@ -7,7 +7,7 @@ Inline bit operations and reduce instruction count to make these hot
 operations faster
 
 diff --git a/src/main/java/net/minecraft/server/BlockPosition.java b/src/main/java/net/minecraft/server/BlockPosition.java
-index 163a6c83a2e494e28981974ef9accd3255e562c2..551ca4471fa3e80fd812938bfce53ca1854dc94d 100644
+index 163a6c83a2e494e28981974ef9accd3255e562c2..8c2a4b57aba17b43517f7b09c4adf65ae5904b6d 100644
 --- a/src/main/java/net/minecraft/server/BlockPosition.java
 +++ b/src/main/java/net/minecraft/server/BlockPosition.java
 @@ -53,28 +53,29 @@ public class BlockPosition extends BaseBlockPosition {
@@ -31,7 +31,7 @@ index 163a6c83a2e494e28981974ef9accd3255e562c2..551ca4471fa3e80fd812938bfce53ca1
  
      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) {