remove unused fluid chunk function

src/main/java/electrosphere/client/fluid/cache/FluidChunkData.java

@@ -57,14 +57,4 @@ public class FluidChunkData {
         return voxelWeight[x][y][z];
     }
 
-    /**
-     * Gets a key for the modifiedSinceLastGeneration set based on a voxel position
-     * @param position The voxel position
-     * @return The key
-     */
-    private String getVoxelPositionKey(Vector3i position){
-        return position.x + "_" + position.y + "_" + position.z;
-    }
-
-
 }