Better reverse proxy support.

wled00/data/settings_sync.htm

@@ -67,9 +67,11 @@
 			// detect reverse proxy
 			let paths = l.pathname.slice(1,l.pathname.endsWith('/')?-1:undefined).split("/");
 			if (paths.length > 2) {
+				paths.pop(); // remove "sync"
+				paths.pop(); // remove "settings"
 				locproto = l.protocol;
 				loc = true;
-				locip = l.hostname + (l.port ? ":" + l.port : "") + "/" + paths[0];
+				locip = l.hostname + (l.port ? ":" + l.port : "") + "/" + paths.join('/');
 			}
 		}
 		loadJS(getURL('/settings/s.js?p=4'), false);	// If we set async false, file is loaded and executed, then next statement is processed