Allow pdf uploads
Revert "Allow pdf uploads"

This reverts commit f122cc78bb78a989ea2b86f68c856882b010968a.
Revert "Revert "Allow pdf uploads""

This reverts commit 433a247efb77c56e6a44df9f9800fc0c094e2314.
Revert "Revert "Revert "Allow pdf uploads"""

This reverts commit 9ded920df19639150082d2756052b59e8c6f6d5d.