Fix Flake8 E275 error

[heavenshell]

ref #636 #637

CI was failing by flake8 error.
https://github.com/hhatto/autopep8/runs/7632859252?check_suite_focus=true

autopep8.py:3699:41: E275 missing whitespace after keyword

This PR just fix flake8 error.
Please check this 🙏

[codecov-commenter]

Codecov Report

Merging #639 (4dc2235) into master (74da7ae) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #639   +/-   ##
=======================================
  Coverage   97.83%   97.83%           
=======================================
  Files           1        1           
  Lines        2406     2406           
=======================================
  Hits         2354     2354           
  Misses         52       52           

Impacted Files	Coverage Δ
autopep8.py	97.83% <ø> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 74da7ae...4dc2235. Read the comment docs.

[hhatto]

LGTM 👍