conf: Fix layout warnings

QLayout: Attempting to add QLayout "" to DlgGeneral "", which already has a layout
QLayout: Attempting to add QLayout "" to DlgPresentation "", which already has a layout

part/dlggeneral.cpp

@@ -79,7 +79,7 @@ DlgGeneral::DlgGeneral(QWidget *parent, Okular::EmbedMode embedMode)
     KColorButton *customColor = new KColorButton(this);
     customColor->setObjectName(QStringLiteral("kcfg_BackgroundColor"));
 
-    QHBoxLayout *customColorLayout = new QHBoxLayout(this);
+    QHBoxLayout *customColorLayout = new QHBoxLayout();
     customColorLayout->addWidget(useCustomColor);
     useCustomColor->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     customColorLayout->addWidget(customColor);

part/dlgpresentation.cpp

@@ -41,7 +41,7 @@ DlgPresentation::DlgPresentation(QWidget *parent)
     advanceTime->setSuffix(ki18ncp("Advance every %1 seconds", " second", " seconds"));
     advanceTime->setObjectName(QStringLiteral("kcfg_SlidesAdvanceTime"));
 
-    QHBoxLayout *advanceAutomaticallyLayout = new QHBoxLayout(this);
+    QHBoxLayout *advanceAutomaticallyLayout = new QHBoxLayout();
     advanceAutomaticallyLayout->addWidget(advanceAutomatically);
     advanceAutomatically->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     advanceAutomaticallyLayout->addWidget(advanceTime);