installation: fix for Solr 3.1.0 distribution URL
installation: fix for Solr 3.1.0 distribution URL

Co-authored-by: Patrick Glauner <5443b88bc6611431eef05c8ef00b7fee188ca13d@cern.ch>

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