Fix bug uploading empty directories for deepmodeling/dpgen#1180 (#322)

Items in `directory_list` are dealt with in the same way as `file_list`
during `_walk_directory()`. However, items in it were not converted back
to relavent path pattern while `file_list` did, causing bug when
uploading an empty directory. In DP-GEN process, each Lammps task
contains an empty `traj` directory, and thus, it will be passed into
`tar.add()` with wrong `ii` and moreover, wrong `arcname`.

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

dpdispatcher/ssh_context.py

@@ -565,7 +565,7 @@ def upload(
         file_list = []
         directory_list = []
         for task in submission.belonging_tasks:
-            directory_list.append(task.task_work_path)
+            directory_list.append(os.path.join(self.local_root, task.task_work_path))
             #     file_list.append(ii)
             self._walk_directory(
                 task.forward_files,
@@ -577,6 +577,9 @@ def upload(
             submission.forward_common_files, self.local_root, file_list, directory_list
         )
 
+        # convert to relative path to local_root
+        directory_list = [os.path.relpath(jj, self.local_root) for jj in directory_list]
+
         # check if the same file exists on the remote file
         # only check sha256 when the job is recovered
         if recover: