Fix Nightlight sleep timer to default

Based on WLED API (https://kno.wled.ge/interfaces/http-api/) current handler uses NL=1 so sleep timer is hard coded to 1 minute. Should be default (ND) to use configured time in WLED.

Fixes #11389

Signed-off-by: Sven Jensen <github@s7j.de>

bundles/org.openhab.binding.wled/src/main/java/org/openhab/binding/wled/internal/WLedHandler.java

@@ -387,7 +387,7 @@ public void handleCommand(ChannelUID channelUID, Command command) {
                 break;
             case CHANNEL_SLEEP:
                 if (OnOffType.ON.equals(command)) {
-                    sendGetRequest("/win&NL=1");
+                    sendGetRequest("/win&ND");
                 } else {
                     sendGetRequest("/win&NL=0");
                 }