[mms] SECURITY: Fix XSS vulnerability in Horde_Crypt_Smime#certToHTML() (João Machado <geral@jpaulo.eu>).

Signed-off-by: Michael M Slusarz <slusarz@horde.org>
Released Horde_Crypt-2.2.1
Development mode for Horde_Crypt-2.2.2