More compilation fixes for new wxRTC image code without PCH.

Add more headers needed when not using PCH.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65681 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/richtext/richtextimagedlg.cpp

@@ -19,6 +19,8 @@
 #ifndef WX_PRECOMP
     #include "wx/button.h"
     #include "wx/combobox.h"
+    #include "wx/sizer.h"
+    #include "wx/stattext.h"
     #include "wx/textctrl.h"
 #endif