Revert "qt: Added firstrun wizard into MainInterface"

This reverts commit 3895e912bf.

This broke the test suite:

[00007f6d0c000f20] idummy access: command `nop'
vlc: ../../modules/gui/qt/dialogs/firstrun/firstrunwizard.cpp :308 : virtual void FirstRunWizard::reject():  l'assertion « p_intf->p_mi » a échoué.
Aborted

modules/gui/qt/dialogs/dialogs_provider.cpp

@@ -54,7 +54,6 @@
 #include "dialogs/epg/epg.hpp"
 #include "dialogs/errors/errors.hpp"
 #include "dialogs/playlists/playlists.hpp"
-#include "dialogs/firstrun/firstrunwizard.hpp"
 
 #include <QEvent>
 #include <QApplication>
@@ -263,13 +262,6 @@ void DialogsProvider::prefsDialog()
     p->toggleVisible();
 }
 
-void DialogsProvider::firstRunDialog()
-{
-    FirstRunWizard *p = new FirstRunWizard( p_intf );
-    QVLCDialog::setWindowTransientParent(p, nullptr, p_intf);
-    p->show();
-}
-
 void DialogsProvider::extendedDialog()
 {
     ExtendedDialog *extDialog = ExtendedDialog::getInstance(p_intf );

modules/gui/qt/dialogs/dialogs_provider.hpp

@@ -136,7 +136,6 @@ public slots:
     void mediaInfoDialog( const PlaylistItem& pItem );
     void mediaCodecDialog();
     void prefsDialog();
-    void firstRunDialog();
     void extendedDialog();
     void synchroDialog();
     void messagesDialog();

modules/gui/qt/maininterface/main_interface.cpp

@@ -206,14 +206,6 @@ MainInterface::MainInterface(qt_intf_t *_p_intf)
 
     /* Register callback for the intf-popupmenu variable */
     var_AddCallback( libvlc, "intf-popupmenu", PopupMenuCB, p_intf );
-
-    if( config_GetInt("qt-privacy-ask") )
-    {
-        //postpone dialog call, as composition might not be ready yet
-        QMetaObject::invokeMethod(this, [this](){
-            THEDP->firstRunDialog();
-        }, Qt::QueuedConnection);
-    }
 }
 
 MainInterface::~MainInterface()