Fix fog density being 2.0f instead of 1.8f (Thanks gDEBugger)

Author: UnknownShadow200

fCraft/World/DefaultSet.cs

@@ -61,7 +61,7 @@ public static byte FogDensity(Block b) {
             if (b == Block.Water || b == Block.StillWater)
                 return 11; // (128 * 0.1f - 1);
             if (b == Block.Lava || b == Block.StillLava)
-                return 255; // (128 * 2 - 1);
+                return 229; // (128 * 1.8f - 1);
             return 0;
         }