TechDraw: fix build for qt4

src/Mod/TechDraw/Gui/TaskRichAnno.cpp

@@ -90,6 +90,11 @@ TaskRichAnno::TaskRichAnno(TechDrawGui::ViewProviderRichAnno* annoVP) :
     }
     ui->setupUi(this);
     
+#if QT_VERSION >= 0x050200
+    ui->teAnnoText.setPlaceholderText(QObject::tr(
+                "Input the annotation text directly or start the rich text editor"));
+#endif
+
     m_annoFeat = m_annoVP->getFeature();
 
     //m_baseFeat can be null