Wordpress-ios: Upload Media button doesn't work with empty media library

[hoverduck]

Expected behavior

To be able to upload media

Actual behavior

There's no response

Steps to reproduce the behavior

Open a site with no media and try to click the Upload Media button

Tested on iPad Air 2, iOS 10.3.1, WPiOS 7.7.0.20170522

[kurzee]

This is internal only, coming in https://github.com/wordpress-mobile/WordPress-iOS/pull/7225