uic: Generate include statement for QActionGroup

Legacy forms from Qt 3 may still contain QActionGroup,
generate an include statement for them.

Change-Id: I292967f23f798a132ec7e360e437b20a529c3a26
Complements: bcaff2b06f
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/tools/uic/cpp/cppwriteincludes.cpp

@@ -255,7 +255,7 @@ void WriteIncludes::acceptCustomWidget(DomCustomWidget *node)
 
 void WriteIncludes::acceptActionGroup(DomActionGroup *node)
 {
-    add(QLatin1String("QAction"));
+    add(QLatin1String("QActionGroup"));
     TreeWalker::acceptActionGroup(node);
 }