Fix default sky-light being 16 instead of 15

Author: TBlueF

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/chunk/Chunk_1_13.java

@@ -79,7 +79,7 @@ public Chunk_1_13(MCAWorld world, Data data) {
         this.inhabitedTime = level.inhabitedTime;
 
         DimensionType dimensionType = getWorld().getDimensionType();
-        this.skyLight = dimensionType.hasSkylight() ? 16 : 0;
+        this.skyLight = dimensionType.hasSkylight() ? 15 : 0;
 
         this.worldSurfaceHeights = level.heightmaps.worldSurface;
         this.oceanFloorHeights = level.heightmaps.oceanFloor;

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/chunk/Chunk_1_16.java

@@ -75,7 +75,7 @@ public Chunk_1_16(MCAWorld world, Data data) {
         this.inhabitedTime = level.inhabitedTime;
 
         DimensionType dimensionType = getWorld().getDimensionType();
-        this.skyLight = dimensionType.hasSkylight() ? 16 : 0;
+        this.skyLight = dimensionType.hasSkylight() ? 15 : 0;
 
         int worldHeight = dimensionType.getHeight();
         int bitsPerHeightmapElement = MCAUtil.ceilLog2(worldHeight + 1);

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/chunk/Chunk_1_18.java

@@ -74,7 +74,7 @@ public Chunk_1_18(MCAWorld world, Data data) {
 
         DimensionType dimensionType = getWorld().getDimensionType();
         this.worldMinY = dimensionType.getMinY();
-        this.skyLight = dimensionType.hasSkylight() ? 16 : 0;
+        this.skyLight = dimensionType.hasSkylight() ? 15 : 0;
 
         int worldHeight = dimensionType.getHeight();
         int bitsPerHeightmapElement = MCAUtil.ceilLog2(worldHeight + 1);