Damaged Link in `examples/with-pdf/App.js`

[Jemeni11]

https://github.com/expo/examples/blob/18407f8f0b289d896a12ede4195e83bed9c4118c/with-pdf/App.js#L5

The link to the pdf gives this error when opened in a browser: This server could not prove that it is samples.leanpub.com; its security certificate is from s3.amazonaws.com. This may be caused by a misconfiguration or an attacker intercepting your connection.