Update urllib3 to 1.25.11

[pyup-bot]

This PR updates urllib3 from 1.25.9 to 1.25.11.

Changelog

1.25.11

--------------------

* Fix retry backoff time parsed from ``Retry-After`` header when given
in the HTTP date format. The HTTP date was parsed as the local timezone
rather than accounting for the timezone in the HTTP date (typically
UTC) (Pull 1932, Pull 1935, Pull 1938, Pull 1949)

* Fix issue where an error would be raised when the ``SSLKEYLOGFILE``
environment variable was set to the empty string. Now ``SSLContext.keylog_file``
is not set in this situation (Pull 2016)

1.25.10

--------------------

* Added support for ``SSLKEYLOGFILE`` environment variable for
logging TLS session keys with use with programs like
Wireshark for decrypting captured web traffic (Pull 1867)

* Fixed loading of SecureTransport libraries on macOS Big Sur
due to the new dynamic linker cache (Pull 1905)

* Collapse chunked request bodies data and framing into one
call to ``send()`` to reduce the number of TCP packets by 2-4x (Pull 1906)

* Don't insert ``None`` into ``ConnectionPool`` if the pool
was empty when requesting a connection (Pull 1866)

* Avoid ``hasattr`` call in ``BrotliDecoder.decompress()`` (Pull 1858)

Links

• PyPI: https://pypi.org/project/urllib3
• Changelog: https://pyup.io/changelogs/urllib3/
• Docs: https://urllib3.readthedocs.io/

[pyup-bot]

Closing this in favor of #1368