WS280 29:UniProt paper file availability on the FTP copies is mind-boggling

[MagdalenaZZ]

For both Sratti and Ovolvolus the files are empty, but they have nevertheless very inconsistently been available or unavailable the last 10 build cycles.

(base) -bash-4.2$ ls -l /nfs/ftp/pub/databases/wormbase/releases/WS2*/species/o_volvulus/PRJEB513/annotation/uniprot_papers

Action: Make FTP script needs to check for these files. Empty files should be flagged/warned.
Action: Boiler plate "No data" in empty files.
Action: Add the FTP-checking script to the build.