Coverity issues:

129097
129098
129099
129101
129102
129132
129134
129203

src/Gui/WidgetFactory.cpp

@@ -390,8 +390,11 @@ QWidget* WidgetFactoryInst::createPrefWidget(const char* sName, QWidget* parent,
     w->setParent(parent);
 
     try {
-        dynamic_cast<PrefWidget*>(w)->setEntryName(sPref);
-        dynamic_cast<PrefWidget*>(w)->restorePreferences();
+        PrefWidget* pw = dynamic_cast<PrefWidget*>(w);
+        if (pw) {
+            pw->setEntryName(sPref);
+            pw->restorePreferences();
+        }
     }
     catch (...) {
 #ifdef FC_DEBUG