main: Linux - ask to create desktop entry on the first start

src/qt/utils.h

@@ -39,8 +39,8 @@ QByteArray fileOpen(QString path);
 bool fileWrite(QString path, QString data);
 QString getAccountName();
 #ifdef Q_OS_LINUX
-QString xdgMime(QApplication &app);
-void registerXdgMime(QApplication &app);
+QString xdgMime();
+void registerXdgMime();
 #endif
 const static QRegExp reURI = QRegExp("^\\w+:\\/\\/([\\w+\\-?\\-_\\-=\\-&]+)");
 QString randomUserAgent();