Remove temporary directory for file downloading

src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala

@@ -683,11 +683,6 @@ trait RepositoryViewerControllerBase extends ControllerBase {
 
   private def archiveRepository(name: String, suffix: String, repository: RepositoryService.RepositoryInfo): Unit = {
     val revision = name.stripSuffix(suffix)
-    val workDir = getDownloadWorkDir(repository.owner, repository.name, session.getId)
-    if(workDir.exists) {
-      FileUtils.deleteDirectory(workDir)
-    }
-    workDir.mkdirs
 
     val filename = repository.name + "-" +
       (if(revision.length == 40) revision.substring(0, 10) else revision).replace('/', '_') + suffix

src/main/scala/gitbucket/core/util/Directory.scala

@@ -72,12 +72,6 @@ object Directory {
    */
   def getPluginCacheDir(): File = new File(s"${TemporaryHome}/_plugins")
 
-  /**
-   * Temporary directory which is used to create an archive to download repository contents.
-   */
-  def getDownloadWorkDir(owner: String, repository: String, sessionId: String): File = 
-    new File(getTemporaryDir(owner, repository), s"download/${sessionId}")
-  
   /**
    * Substance directory of the wiki repository.
    */