Fix documentation for tlsext_ticket_key
The tlsext_ticket_key functions are documented as returning 0 on success.
In fact they return 1 on success.
@@ -145,7 +145,7 @@ enable an attacker to obtain the session keys.
=head1 RETURN VALUES
-returns 0 to indicate the callback function was set.
+Returns 1 to indicate the callback function was set and 0 otherwise.
=head1 EXAMPLES
