REST PDF export throws 500 error
Description
In our installation of 2.5.1 the following curl command returns a valid pdf: `curl -H "X-ArchivesSpace-Session: $S" -O localhost:8089/repositories/2/resource_descriptions/555.pdf`
However, in 2.6.0, the same call (for a different but valid resource) it throws a 500 error "wrong number of arguments (1 for 2)" originating from "app/lib/AS_fop.rb:16:in `initialize'" .
Below is the relevant archivesspace.log output:
Environment
ArchivesSpace 2.6.0 on Ubuntu 18 using MySQL 5.7.26. (Installed on 2018-07-02.)
