Revert "Fix HMCL-dev#2687 (HMCL-dev#2688)"

This reverts commit 207b4d0.

HMCL/src/main/java/org/jackhuang/hmcl/ui/nbt/NBTFileType.java

@@ -9,7 +9,6 @@
 import org.jackhuang.hmcl.util.io.FileUtils;
 
 import java.io.*;
-import java.util.Arrays;
 import java.util.zip.GZIPInputStream;
 import java.util.zip.Inflater;
 import java.util.zip.InflaterInputStream;
@@ -18,22 +17,8 @@ public enum NBTFileType {
     COMPRESSED("dat", "dat_old") {
         @Override
         public Tag read(File file) throws IOException {
-            try (BufferedInputStream fileInputStream = new BufferedInputStream(new FileInputStream(file))) {
-                fileInputStream.mark(3);
-                byte[] header = new byte[3];
-                if (fileInputStream.read(header) < 3) {
-                    throw new IOException("File is too small");
-                }
-                fileInputStream.reset();
-
-                InputStream input;
-                if (Arrays.equals(header, new byte[]{0x1f, (byte) 0x8b, 0x08})) {
-                    input = new GZIPInputStream(fileInputStream);
-                } else {
-                    input = fileInputStream;
-                }
-
-                Tag tag = NBTIO.readTag(input);
+            try (InputStream in = new GZIPInputStream(new FileInputStream(file))) {
+                Tag tag = NBTIO.readTag(in);
                 if (!(tag instanceof CompoundTag))
                     throw new IOException("Unexpected tag: " + tag);
                 return tag;