typing: suppress a few attribute errors in url.py
These are newly detected by pytype 2022.03.21. Not sure what is going on here-
`realhostport` and `headers` are added outside of the constructor, so that makes
sense. But PyCharm also thinks the private methods don't exist, though when
clicking through the class hierarchy, it shows in the py3.9 source code.
BasedOnStyle: LLVM
IndentWidth: 8
UseTab: ForIndentation
BreakBeforeBraces: Linux
AllowShortIfStatementsOnASingleLine: false
IndentCaseLabels: false
AllowShortBlocksOnASingleLine: false
AllowShortFunctionsOnASingleLine: false
IncludeCategories:
- Regex: '^<'
Priority: 1
- Regex: '^"'
Priority: 2