refactor: some Application & style things (#5561)

src/common/network/NetworkRequest.cpp

@@ -4,6 +4,7 @@
 #include "common/QLogging.hpp"
 #include "common/Version.hpp"
 
+#include <QApplication>
 #include <QDebug>
 #include <QFile>
 #include <QtConcurrent>
@@ -44,7 +45,7 @@ NetworkRequest NetworkRequest::caller(const QObject *caller) &&
     if (caller)
     {
         // Caller must be in gui thread
-        assert(caller->thread() == qApp->thread());
+        assert(caller->thread() == QApplication::instance()->thread());
 
         this->data->caller = const_cast<QObject *>(caller);
         this->data->hasCaller = true;