Fixes <https://issues.guix.gnu.org/55707>.
Previously Inetutils' syslogd would call 'fsync' after each line written
to a file. This would significantly increase boot times on machines
with slow-ish spinning HDDs, where each 'fsync' call would take between
0.1s and 0.4s (and we'd do two of them for each line, one for
/var/log/messages and one for /var/log/debug).
* gnu/services/base.scm (%default-syslog.conf): Add a '-' before each
file name, except /var/log/secure. Change what goes to /var/log/debug.
264ca9452f