Gui: [skip ci] for quick search don't change font family and size but set to bold only because on some systems an almost unreadable font might be taken

src/Gui/DlgParameterImp.cpp

@@ -122,6 +122,8 @@ DlgParameterImp::DlgParameterImp( QWidget* parent,  Qt::WindowFlags fl )
     // store the current font properties because
     // we don't know what style sheet the user uses for FC
     defaultFont = paramGroup->font();
+    boldFont = defaultFont;
+    boldFont.setBold(true);
     defaultColor = paramGroup->topLevelItem(0)->foreground(0);
 
     // set a placeholder text to inform the user

src/Gui/DlgParameterImp.h

@@ -78,7 +78,7 @@ protected:
 private:
     QFont defaultFont;
     QBrush defaultColor;
-    const QFont boldFont = QFont(QString(), -1, QFont::Bold);
+    QFont boldFont;
     QList<QTreeWidgetItem*> foundList;
 };