修复 Unzipper 解压空 zip 文件时抛出异常的问题 (#5267)

HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/Unzipper.java

@@ -152,7 +152,7 @@ public final class Unzipper {
                 }
             }
 
-            if (entryCount == 0 && !terminateIfSubDirectoryNotExists) {
+            if (entryCount == 0 && !"/".equals(subDirectory) && !terminateIfSubDirectoryNotExists) {
                 throw new NoSuchFileException("Subdirectory " + subDirectory + " does not exist in the zip file.");
             }
         }