Fix crash when the adapter changes its content

[sgc-code]

PagerAdapterWrappershould call super.notifyDataSetChanged()when a change happens in the wrapped PageAdapter otherwise you get the following error:

The application's PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged

[Ereza]

Thanks a lot! We has this problem and this change fixes it! I hope it gets merged soon!

[Nammari]

Unfortunately this does not fix the crash !!!