add sortBy=noSort for query flags

fixes: https://github.com/wiedehopf/tar1090/issues/409

README-query.md

@@ -23,7 +23,7 @@
 - filterIcao=^a - filter icao that start with a (escape with %5Ea).
 - filterSources=adsb,uat,adsr,mlat,tisb,modeS - filter planes by source type.
 - filterDbFlag=military,pia,ladd - filter planes by the db flags.
-- sortBy=column - (possible values: icao, flag, flight, registration, aircraft_type, squawk, altitude, speed, vert_rate, distance, track, msgs, seen, rssi, lat, lon, data_source, military, ws, wd
+- sortBy=column - (possible values: icao, flag, flight, registration, aircraft_type, squawk, altitude, speed, vert_rate, distance, track, msgs, seen, rssi, lat, lon, data_source, military, ws, wd, noSort)
 - sortByReverse - reverse the sorting specified using sortBy
 
 There is a setting in the webinterface to update the URL according to used filters, this can be simpler than building the query string by hand.

html/script.js

@@ -6991,7 +6991,9 @@ function initSitePos() {
     if (initSitePosFirstRun) {
         initSitePosFirstRun = false;
         const sortBy = usp.get('sortBy');
-        if (sortBy) {
+        if (sortBy == "nosort" ) {
+            // no sorting
+        } else if (sortBy) {
             TAR.planeMan.ascending = true;
             TAR.planeMan.cols[sortBy].sort();
             if (usp.has('sortByReverse')) {