void tls_deinit_connection(object ob)
tls_deinit_connection() shuts down a TLS connection to
the interactive object <ob> (or this_object() if <ob> is not
given) but the connection is not closed.
Under normal circumstances there is no need to use this efun: most
clients operate in either secure or unsecure mode, but don't allow
switching connection security on the fly.
Introduced in LDMud 3.3.474 and following, backported to 3.2.11.
tls_init_connection(E), tls_error(E), tls_query_connection_state(E),