Default transfer block should be 8192

https://android.googlesource.com/platform/libcore/+/refs/heads/master/ojluni/src/main/java/sun/nio/ch/FileChannelImpl.java#707

app/src/main/java/com/hippo/ehviewer/spider/SpiderDen.kt

@@ -323,7 +323,7 @@ class SpiderDen(private val mGalleryInfo: GalleryInfo) {
     }
 
     companion object {
-        private const val TRANSFER_BLOCK: Long = 40960
+        private const val TRANSFER_BLOCK: Long = 8192
 
         // We use data to store image file, and metadata for image type
         private val sCache by lazy {
@@ -365,4 +365,4 @@ class SpiderDen(private val mGalleryInfo: GalleryInfo) {
             return null
         }
     }
-}
+}