Fix spurious .pid file error in linux-sysvinit

This change eliminates the `[ERROR] Could not write pidfile: open /var/run/caddy.pid: permission denied` from caddy.log.
The start-stop-daemon writes the file as root so the DAEMONUSER that caddy runs as cannot write to the .pid file.

dist/init/linux-sysvinit/caddy

@@ -20,7 +20,7 @@ DAEMONUSER=www-data
 PIDFILE=/var/run/$NAME.pid
 LOGFILE=/var/log/$NAME.log
 CONFIGFILE=/etc/caddy/Caddyfile
-DAEMONOPTS="-agree=true -pidfile=$PIDFILE -log=$LOGFILE -conf=$CONFIGFILE"
+DAEMONOPTS="-agree=true -log=$LOGFILE -conf=$CONFIGFILE"
 
 USERBIND="setcap cap_net_bind_service=+ep"
 STOP_SCHEDULE="${STOP_SCHEDULE:-QUIT/5/TERM/5/KILL/5}"