Revert "solr: Filter spider IPs in stats"

This reverts commit 135bed242cd8f1cd7bd5ff1655969f1e5ba40e0d.

Causes extremely long SOLR queries which time out, we need to look
at pruning the stats offline, ie:

    dspace status-util -f
or

    dspace status-util -i

See:
    https://wiki.duraspace.org/display/DSDOC3x/Managing+Usage+Statistics