bpo-39006: Fix asyncio when the ssl module is missing (GH-17524)


Fix asyncio when the ssl module is missing: only check for
ssl.SSLSocket instance if the ssl module is available.
(cherry picked from commit 82b4950b5e92bec343a436b3f9c116400b66e1b9)

Co-authored-by: Victor Stinner <vstinner@python.org>
2 files changed