Fix session resumption issue when using external cache
I found that the session resumption process may become corrupted when
using external cache for version >= 1.1.0. It is almost ensure that all
valid SSL_SESSION returned by get_session_cb() will cause session
resumption failing unless SSL_SESS_CACHE_NO_INTERNAL_STORE is set. A PR
has been filed to solve this problem:
https://github.com/openssl/openssl/pull/4014 . The description of the PR
should be enough.