fix web service optional array parameters were always transformed to arrays

git-svn-id: http://piwigo.org/svn/trunk@21965 68402e56-0260-453c-a942-63ccdbb3a9ee
use right flag for sl_SI

git-svn-id: http://piwigo.org/svn/trunk@21983 68402e56-0260-453c-a942-63ccdbb3a9ee