Send all rechecks in one request

src/webui/www/private/scripts/mocha-init.js

@@ -387,15 +387,13 @@ initializeWindows = function() {
     recheckFN = function() {
         var hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
-            hashes.each(function(hash, index) {
             new Request({
                 url: 'api/v2/torrents/recheck',
                 method: 'post',
                 data: {
-                        hashes: hash
+                    hashes: hashes.join("|"),
                 }
             }).send();
-            });
             updateMainData();
         }
     };