Fix code defects

src/webui/www/private/rename_files.html

@@ -68,8 +68,10 @@
         }
 
         // Register keyboard events to modal window
+        // https://github.com/qbittorrent/qBittorrent/pull/18687#discussion_r1135045726
+        var keyboard;
         if (!keyboard) {
-            var keyboard = new Keyboard({
+            keyboard = new Keyboard({
                 defaultEventType: 'keydown',
                 events: {
                     'Escape': function(event) {

src/webui/www/private/scripts/piecesbar.js

@@ -106,7 +106,6 @@ window.qBittorrent.PiecesBar = (() => {
     }
 
     function refresh(force) {
-        const start = Date.now();
         if (!this.parentNode)
             return;
 

src/webui/www/private/scripts/prop-files.js

@@ -564,7 +564,7 @@ window.qBittorrent.PropFiles = (function() {
     };
 
     const multiFileRename = function(hash) {
-        const win = new MochaUI.Window({
+        new MochaUI.Window({
             id: 'multiRenamePage',
             title: "QBT_TR(Renaming)QBT_TR[CONTEXT=TorrentContentTreeView]",
             data: { hash: hash, selectedRows: torrentFilesTable.selectedRows },