In 1fce1c3c73, we added logic to parse
the User-Agent in /register requests; this logic crashed if an HTTP request
was missing that header.
Includes a test for `/register` with no user agent passed; this should catch
similar regressions in the future.
Co-authored-by: Mateusz Mandera <mateusz.mandera@zulip.com>
Mobile clients older than v27.192 do not support PRONOUNS type
custom profile fields, so we instead change the type of it to
SHORT_TEXT in the data sent with register response and also in
the events sent to those clients.
Shift functions used for compatibility from
zerver.lib.home (is_outdated_server) and
zerver.view.compatibility (pop_numerals,
version_lt, find_mobile_os,
is_outdated_desktop_app, is_unsupported_browser)
to zerver.lib.compatibility module.
