Use source URL for search plugins

This saves a few URL redirections. And avoids potential issues related to Cloudflare
protections/blockages on qbt domain.

Closes #22990.
PR #23048.

src/base/search/searchpluginmanager.cpp

@@ -87,7 +87,7 @@ namespace
 QPointer<SearchPluginManager> SearchPluginManager::m_instance = nullptr;
 
 SearchPluginManager::SearchPluginManager()
-    : m_updateUrl(u"https://searchplugins.qbittorrent.org/nova3/engines/"_s)
+    : m_updateUrl(u"https://raw.githubusercontent.com/qbittorrent/search-plugins/refs/heads/master/nova3/engines/"_s)
     , m_proxyEnv {QProcessEnvironment::systemEnvironment()}
 {
     Q_ASSERT(!m_instance); // only one instance is allowed

src/webui/www/private/views/preferences.html

@@ -2127,9 +2127,11 @@ Use ';' to split multiple entries. Can use wildcard '*'.)QBT_TR[CONTEXT=OptionsD
         };
 
         const generateRandomPort = () => {
-            const min = 1024;
-            const max = 65535;
-            const port = Math.floor(Math.random() * (max - min + 1) + min);
+            // don't use modulo operations to avoid 'modulo bias'
+            const buffer = new Uint16Array(1);
+            let port = crypto.getRandomValues(buffer)[0];
+            while (port < 1024)
+                port = crypto.getRandomValues(buffer)[0];
             document.getElementById("portValue").value = port;
         };