Fix ARCUtil.Inject to reset stream pos

PCK-Studio/Classes/Utils/ARC/ARCUtil.cs

@@ -15,6 +15,7 @@ namespace PckStudio.Classes.Utils.ARC
             using (var fs = File.Open(filepath, FileMode.Open, FileAccess.ReadWrite))
             {
                 var archive = ARCFileReader.Read(fs);
+                fs.Seek(0, SeekOrigin.Begin);
                 archive.Add(entry.filepath, entry.data);
                 ARCFileWriter.Write(fs, archive);
             }