Bug#997972: haskell-pandoc-citeproc has been deprecated upstream

[Bastian Germann]

Control: retitle -1 RM: haskell-pandoc-citeproc -- RoQA; not needed; upstream 
dead
Control: reassign -1 ftp.debian.org

I have just uploaded the last reverse dependencies pypandoc and pigx-rnaseq 
with changes to get rid of pandoc-citeproc.