classifer: fix classifer registry name

* Fixes the name of the classifer registry which accidentially
  was discovered by bibconvert registry due to name clash.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Tested-by: Jiri Kuncar <jiri.kuncar@cern.ch>
BibDocFile: hotfix plugins loading

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>