Force write.lock files to be removed on Solr core registration.
Force write.lock files to be removed on Solr core registration.

If the system has crashed while indexing, write.lock files remain and
had to be removed manually up to now. The unlock works only with the
Native locks we use at the moment.
gallardo/opencms-core,alkacon/opencms-core,gallardo/opencms-core,gallardo/opencms-core,alkacon/opencms-core,alkacon/opencms-core,alkacon/opencms-core,gallardo/opencms-core