Fix sadfaces, and remove some missing imports

A recent change caused the miniblog to start generating sadfaces,
and this fixes them. I also removed some unused imports that I noticed
while working on #1516.
Add comment to explain cache error fix
Merge branch 'main' into fix-imports

Conflicts:
	esp/esp/web/util/main.py
Merge pull request #1517 from learning-unlimited/fix-imports

Fix sadfaces, and remove some missing imports