Qt4: fix remaining preferences intempestive popups.

(cherry picked from commit 9e43b17d)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/components/complete_preferences.cpp

@@ -457,7 +457,7 @@ AdvPrefsPanel::AdvPrefsPanel( intf_thread_t *_p_intf, QWidget *_parent,
                 layout->addWidget( box, i_line, 0, 1, -1 );
                 i_line++;
             }
-            box = new QGroupBox( qtr( p_item->psz_text ) );
+            box = new QGroupBox( qtr( p_item->psz_text ), this );
             box->hide();
             boxlayout = new QGridLayout();
         }

modules/gui/qt4/components/preferences_widgets.cpp

@@ -613,7 +613,7 @@ ModuleListConfigControl::ModuleListConfigControl( vlc_object_t *_p_this,
     /* Special Hack */
     if( !p_item->psz_text ) return;
 
-    groupBox = new QGroupBox ( qtr(p_item->psz_text) );
+    groupBox = new QGroupBox ( qtr(p_item->psz_text), _parent );
     text = new QLineEdit;
     QGridLayout *layoutGroupBox = new QGridLayout( groupBox );