Change FossHub RSS url for updates

The new RSS format is compatible with our current parser. FossHub will
redirect old URL to the new one so older clients will not be affected.

src/gui/programupdater.cpp

@@ -41,7 +41,7 @@
 
 namespace
 {
-    const QString RSS_URL {QStringLiteral("https://www.fosshub.com/software/feedqBittorent")};
+    const QString RSS_URL {QStringLiteral("https://www.fosshub.com/feed/5b8793a7f9ee5a5c3e97a3b2.xml")};
 
     QString getStringValue(QXmlStreamReader &xml);
 }