[plasmalnf] Adjust explanation message to setup mode

Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>

src/modules/plasmalnf/PlasmaLnfPage.cpp

@@ -1,6 +1,7 @@
 /* === This file is part of Calamares - <https://github.com/calamares> ===
  *
  *   Copyright 2017-2018, Adriaan de Groot <groot@kde.org>
+ *   Copyright 2019, Collabora Ltd <arnaud.ferraris@collabora.com>
  *
  *   Calamares is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -22,6 +23,7 @@
 
 #include "utils/Logger.h"
 #include "utils/Retranslator.h"
+#include "Settings.h"
 
 #include <QAbstractButton>
 
@@ -64,6 +66,13 @@ PlasmaLnfPage::PlasmaLnfPage( QWidget* parent )
     CALAMARES_RETRANSLATE(
     {
         ui->retranslateUi( this );
+        if ( Calamares::Settings::instance()->isSetupMode() )
+            ui->generalExplanation->setText( tr(
+                "Please choose a look-and-feel for the KDE Plasma Desktop. "
+                "You can also skip this step and configure the look-and-feel "
+                "once the system is set up. Clicking on a look-and-feel "
+                "selection will give you a live preview of that look-and-feel.") );
+        else
             ui->generalExplanation->setText( tr(
                 "Please choose a look-and-feel for the KDE Plasma Desktop. "
                 "You can also skip this step and configure the look-and-feel "