ddns-scripts: fix option name in updater messages

On master, updater help and missing-option text still refer to '-N'.
Use '-S' instead so the messages match accepted script options.
Also clarify that SECTION is the UCI section name/id to start.
This is a text-only change; runtime behavior is unchanged.

Bump PKG_RELEASE to 4.

Fixes: #27737
Signed-off-by: Dharmik Parmar <dharmikparmar2004@yahoo.com>

net/ddns-scripts/Makefile

@@ -8,7 +8,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ddns-scripts
 PKG_VERSION:=2.8.3
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 
 PKG_LICENSE:=GPL-2.0
 

net/ddns-scripts/files/usr/lib/ddns/dynamic_dns_updater.sh

@@ -23,7 +23,7 @@ Usage:
 
 Parameters:
  -S SECTION          SECTION to start
-                     use either -N NETWORK or -S SECTION
+                     SECTION is the UCI section name/id to start
 
  -h                  show this help and exit
  -V                  show version and exit
@@ -57,7 +57,7 @@ while getopts ":hv:dn:S:V" OPT; do
 done
 shift $((OPTIND - 1 ))	# OPTIND is 1 based
 
-[ -z "$SECTION_ID" ] && usage_err "option '-N' is missing"
+[ -z "$SECTION_ID" ] && usage_err "option '-S' is missing"
 
 # set file names
 PIDFILE="$ddns_rundir/$SECTION_ID.pid"	# Process ID file