MINOR: ssl: Enable error fetches in case of handshake error

MINOR: ssl: Enable error fetches in case of handshake error

The ssl_c_err, ssl_c_ca_err and ssl_c_ca_err_depth sample fetches values
were not recoverable when the connection failed because of the test
"conn->flags & CO_FL_WAIT_XPRT" (which required the connection to be
established). They could then not be used in a log-format since whenever
they would have sent a non-null value, the value fetching was disabled.
This patch ensures that all these values can be fetched in case of
connection failure.