Corrected {collection,field} cache timestamp updating in situations such as database being down.  Now the search engine wakes up properly when the database is up again.
Corrected {collection,field} cache timestamp updating in situations
such as database being down.  Now the search engine wakes up properly
when the database is up again.

inveniosoftware/invenio-search,tiborsimko/invenio-search,inveniosoftware/invenio-records,inveniosoftware/invenio-records,tiborsimko/invenio-records,tiborsimko/invenio-search,inveniosoftware/invenio-search,tiborsimko/invenio-records