webcoll: fix for "--language" option
webcoll: fix for "--language" option

* Fixes cache re-creation for a subset of all available
  languages.  (closes #1399) (PR #2219)

Reviewed-by: Tibor Simko <c7116e45300b163846dc01f3ed02116e3f8ef7a5@cern.ch>

inveniosoftware/invenio,tiborsimko/invenio,tiborsimko/invenio,inveniosoftware/invenio