MINOR: connections: Add a new CO_FL_SSL_NO_CACHED_INFO flag

MINOR: connections: Add a new CO_FL_SSL_NO_CACHED_INFO flag

Add a new flag to connections, CO_FL_SSL_NO_CACHED_INFO, and set it for
checks.
It lets the ssl layer know that he should not use cached informations,
such as the ALPN as stored in the server, or cached sessions.
This wlil be used for checks, as checks may target different servers, or
used a different SSL configuration, so we can't assume the stored
informations are correct.

This should be backported to 3.3, and may be backported up to 2.8 if the
attempts to do session resume by checks is proven to be a problem.