Restore behaviour from commit 36ff232c that was incorrectly removed

In TLSv1.2 and below we should remove an old session from the client
session cache in the event that we receive a new session ticket from the
server.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/6601)

ssl/statem/statem_clnt.c

@@ -2591,6 +2591,7 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
      */
     if (SSL_IS_TLS13(s) || s->session->session_id_length > 0) {
         SSL_SESSION *new_sess;
+
         /*
          * We reused an existing session, so we need to replace it with a new
          * one
@@ -2602,6 +2603,16 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
             goto err;
         }
 
+        if ((s->session_ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) != 0
+                && !SSL_IS_TLS13(s)) {
+            /*
+             * In TLSv1.2 and below the arrival of a new tickets signals that
+             * any old ticket we were using is now out of date, so we remove the
+             * old session from the cache. We carry on if this fails
+             */
+            SSL_CTX_remove_session(s->session_ctx, s->session);
+        }
+
         SSL_SESSION_free(s->session);
         s->session = new_sess;
     }