e.g. when 'browser' is set to a non-empty value and gallery-dl creates
its own SSLContext instance instead of using requests' and urllib3's
defaults.
urllib3 disables this option for its default contexts,
since it does this check on its own.
Fixes "ValueError: Cannot set verify_mode to CERT_NONE when
check_hostname is enabled" when using --no-check-certificate.
(#3614, #4891, #5576)