Examples: Fix tile glitch in minecraft demo. (#22657)

examples/webgl_geometry_minecraft.html

@@ -214,7 +214,7 @@
 
 			function getY( x, z ) {
 
-				return ( data[ x + z * worldWidth ] * 0.2 ) | 0;
+				return ( data[ x + z * worldWidth ] * 0.15 ) | 0;
 
 			}