WebUI: clear timer variable properly

In JS the timer handle pool is reused and therefore require careful handling of it.

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

@@ -37,7 +37,7 @@ window.qBittorrent.PropPeers ??= (() => {
     };
 
     const torrentPeersTable = new window.qBittorrent.DynamicTable.TorrentPeersTable();
-    let loadTorrentPeersTimer;
+    let loadTorrentPeersTimer = -1;
     let syncTorrentPeersLastResponseId = 0;
     let show_flags = true;
 
@@ -109,6 +109,7 @@ window.qBittorrent.PropPeers ??= (() => {
 
     const updateData = function() {
         clearTimeout(loadTorrentPeersTimer);
+        loadTorrentPeersTimer = -1;
         loadTorrentPeersData();
     };