Fix linux-sysvinit script to prevent missing caddy.log

Create /var/log/caddy.log and chown prior to starting caddy.
Caddy running as DAEMONUSER does not have permission to create the /var/log/caddy.log.

dist/init/linux-sysvinit/caddy

@@ -36,6 +36,7 @@ ulimit -n 8192
 
 start() {
     $USERBIND $DAEMON
+    touch $LOGFILE && chown $DAEMONUSER $LOGFILE
     start-stop-daemon --start --quiet --make-pidfile --pidfile $PIDFILE \
         --background --chuid $DAEMONUSER --oknodo --exec $DAEMON -- $DAEMONOPTS
 }