uci: add missing 'option' support to uci_rename()

When using the uci.sh wrapper, allow parameters to match those supported
by the uci binary i.e. "uci rename <config>.<section>[.<option>]=<name>".

Signed-off-by: Tony Ambardar <itugrok@yahoo.com>

package/system/uci/files/lib/config/uci.sh

@@ -118,9 +118,10 @@ uci_add() {
 uci_rename() {
 	local PACKAGE="$1"
 	local CONFIG="$2"
-	local VALUE="$3"
+	local OPTION="$3"
+	local VALUE="$4"
 
-	/sbin/uci ${UCI_CONFIG_DIR:+-c $UCI_CONFIG_DIR} rename "$PACKAGE.$CONFIG=$VALUE"
+	/sbin/uci ${UCI_CONFIG_DIR:+-c $UCI_CONFIG_DIR} rename "$PACKAGE.$CONFIG${VALUE:+.$OPTION}=${VALUE:-$OPTION}"
 }
 
 uci_remove() {