Suppress console output in sample crontab/systemd service files (#379).

Reviewed-on: https://projects.torsion.org/witten/borgmatic/pulls/379

sample/cron/borgmatic

@@ -1,3 +1,3 @@
 # You can drop this file into /etc/cron.d/ to run borgmatic nightly.
 
-0 3 * * * root PATH=$PATH:/usr/bin:/usr/local/bin /root/.local/bin/borgmatic --syslog-verbosity 1
+0 3 * * * root PATH=$PATH:/usr/bin:/usr/local/bin /root/.local/bin/borgmatic --verbosity -1 --syslog-verbosity 1

sample/systemd/borgmatic.service

@@ -57,4 +57,4 @@ LogRateLimitIntervalSec=0
 # Delay start to prevent backups running during boot. Note that systemd-inhibit requires dbus and
 # dbus-user-session to be installed.
 ExecStartPre=sleep 1m
-ExecStart=systemd-inhibit --who="borgmatic" --why="Prevent interrupting scheduled backup" /root/.local/bin/borgmatic --syslog-verbosity 1
+ExecStart=systemd-inhibit --who="borgmatic" --why="Prevent interrupting scheduled backup" /root/.local/bin/borgmatic --verbosity -1 --syslog-verbosity 1