TcpSocketEndpoint: fix peer certificate comparaison

Compare only public Id is not secure enough to ensure
certificate comparaison.
Use a byte-comparaison to verify the peer certificate
during TLS certificate checkings.

Change-Id: Ic90877ba3722e69d833f3adf841b3ebde8e44d9f
Reviewed-by: Nicolas Jäger <nicolas.jager@savoirfairelinux.com>