Fix #6263: html: HTML5Translator crashed with invalid field node

[tk0miya]

Feature or Bugfix

• Bugfix

Purpose

• refs: After update to version 2.0, got an error in HTML5Translator #6263

[codecov]

Codecov Report

Merging #6267 into 2.0.1 will decrease coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##            2.0.1    #6267      +/-   ##
==========================================
- Coverage   83.58%   83.55%   -0.03%     
==========================================
  Files         272      274       +2     
  Lines       39369    39404      +35     
  Branches     5868     5871       +3     
==========================================
+ Hits        32907    32925      +18     
- Misses       5113     5127      +14     
- Partials     1349     1352       +3

Impacted Files	Coverage Δ
sphinx/writers/html5.py	89.51% <100%> (+0.02%)	⬆️
sphinx/__init__.py	73.91% <0%> (ø)
sphinx/make_mode.py	0% <0%> (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 8eca15b...6a87ba4. Read the comment docs.