Handle timeout exception in roundup-server better. A timeout in roundup-server used to generate another exception: OSError: cannot read from timed out object when it tried to reuse the socket that timed out. Now return status 408, a brief message and trigger closing of the socket. Manual testing, no CI. To test used curl -X POST with no --data defined.

# setuptools required for installation - missing from newer base images
setuptools
# human timezones
pytz
# indexer
Whoosh
# xapian is also installed
# extra database support
psycopg2
mysqlclient
redis
# encryption
gpg
# java web tokens
PyJWT
# extra HTTP compression methods
Brotli
zstd
# jinja2 template engine
Jinja2