devd.conf: Remove support for coldsync

The coldsync port was removed in 2012. The last stable release of
coldsync was issued in 2002. Let's get rid of it.

PR: 255051
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30100

(cherry picked from commit 1a212abd54c0e4323f11e3bc2fd94ca26f7e5329)