DS-1906: Adds configurable option to reconvert shibboleth attributes.
Reconvert shibboleth attribute only if it is neither null nor empty.
[DS-1985] Comment in SolrBrowseCreateDAO doesn't match desired behaviour

https://jira.duraspace.org/browse/DS-1985
Merge pull request #469 from tuub/DS-1906

DS-1906: Adds configurable option to reconvert shibboleth attributes.