Do not crash on some system when no proxy is set

src/plugins/welcome/rssfetcher.cpp

@@ -120,7 +120,9 @@ RSSFetcher::RSSFetcher(int maxItems, QObject *parent)
 
 void RSSFetcher::fetch(const QUrl &url)
 {
-    m_http.setProxy(QNetworkProxyFactory::systemProxyForQuery(QNetworkProxyQuery(url)).first());
+    QList<QNetworkProxy> proxies = QNetworkProxyFactory::systemProxyForQuery(QNetworkProxyQuery(url));
+    if (proxies.count() > 0)
+        m_http.setProxy(proxies.first());
     m_http.setHost(url.host());
     QString agentStr = QString("Qt-Creator/%1 (QHttp %2; %3; %4; %5 bit)")
                     .arg(Core::Constants::IDE_VERSION_LONG).arg(qVersion())