MB-42468: Fix unit test failure after moving to openssl 1.1.1b

memcached tries to disconnect the client with:

SSL_accept() returned -1 with error 1: error:1417C0C7:SSL routines:tls_process_client_certificate:peer did not return a certificate

But for some reason we don't detect an error in BIO_do_handshake like
we did before. We do however detect the problem the next time we
try to send a command.

Change-Id: I0ee5698fbe02b410fcdced86387a6bfdeafeacb2
Reviewed-on: http://review.couchbase.org/c/kv_engine/+/139466
Well-Formed: Build Bot <[email protected]>
Reviewed-by: Trond Norbye <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: trondn

tests/testapp/testapp_cert_tests.cc

@@ -158,6 +158,7 @@ TEST_F(SslCertTest, LoginWhenMandatoryWithoutCert) {
     MemcachedConnection connection("127.0.0.1", ssl_port, AF_INET, true);
     try {
         connection.connect();
+        connection.hello("LoginWhenMandatoryWithoutCert", "1.0", "");
         FAIL() << "It should not be possible to connect without certificate";
     } catch (const std::exception&) {
     }