File use_qpdfview.patch of Package kraft

diff --git a/src/portal.cpp b/src/portal.cpp
index 8345564..4a79c8c 100644
--- a/src/portal.cpp
+++ b/src/portal.cpp
@@ -702,8 +702,8 @@ void Portal::slotPrintDocument( const QString& id,  const dbID& archID )
 void Portal::slotOpenPdf( const QString& fileName )
 {
     disconnect( ReportGenerator::self(), SIGNAL( pdfAvailable( const QString& ) ),nullptr, nullptr );
-    QUrl url( fileName );
-    QDesktopServices::openUrl(url);
+    qDebug() << "Staring qpdfview viewer directly.";
+    QProcess::startDetached( "qpdfview", QStringList() << fileName );
 
     // save pdf into a <customer>/<dockind> structure
     if( _currentDoc ) {