when user defines "--file-path=/" this if clause will cause effPath="" ,
thus making exportURL="(...)/pentaho/api/repo/files//download" when it should be "(...)/pentaho/api/repo/files/:/download"

This is needed in order to comply with the REST endpoint pattern "{pathId : .+}/download" at FileResource.doGetFileOrDirAsDownload() (*even though* the downloading of the entire repo is not allowed)