🐛 Bug description [Please make everyone to understand it]

When I'm trying to sync an offline log, it may raise error:
swanlab/data/porter/datastore.py", line 126, in scan
assert pad == pad_check, "invalid padding"
^^^^^^^^^^^^^^^^
AssertionError: invalid padding

This error occurs randomly, while at most of the time, it works.

🧑‍💻 Step to reproduce

swanlab sync ~/swanlog/xxx/

👾 Expected result

Write down the results you expect

🚑 Any additional [like screenshots]

• SwanLab Version:
  swanboard 0.1.8b1
  swankit 0.2.4
  swanlab 0.6.8
• Platform:
  Ubuntu 20.04