nanobsd: remove unmodified copies of ssh config files

Nanobsd included copies of ssh_config and sshd_config.  The former is
identical to the one provided by the base system, and the latter is
identical except for PermitRootLogin, which is updated by nanobsd's
cust_allow_ssh_root anyhow.  Remove nanobsd's copies and use the
existing base system ones.

Reported by:	Jose Luis Duran <jlduran@gmail.com> in D34937
Reviewed by:	Jose Luis Duran <jlduran@gmail.com>, imp
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D36933

(cherry picked from commit 4294299)
(cherry picked from commit 6e6c45e)
(cherry picked from commit a1e39f9)
(cherry picked from commit a8925e0)

crypto/openssh/FREEBSD-upgrade

@@ -103,16 +103,11 @@
     something significant changes or if ssh_namespace.h is out of
     whack.
 
-12) Update nanobsd's copies of the ssh config files:
-
-    tools/tools/nanobsd/rescue/Files/etc/ssh/ssh_config
-    tools/tools/nanobsd/rescue/Files/etc/ssh/sshd_config
-
-13) Check for references to obsolete configuration options
+12) Check for references to obsolete configuration options
     (e.g., ChallengeResponseAuthentication in sshd_config) which
     may exist in release/ scripts.
 
-14) Commit, and hunker down for the inevitable storm of complaints.
+13) Commit, and hunker down for the inevitable storm of complaints.