[XMLSCHEMA-26] Fix return of getNamespaceURI
Patch from Dmitry Repchevsky applied

git-svn-id: https://svn.apache.org/repos/asf/webservices/xmlschema/trunk@1560116 13f79535-47bb-0310-9956-ffa450edef68
Change to 2.1.0 as XMLSCHEMA-26 introduces a slight behavior change which may not be appropriate for a patch

git-svn-id: https://svn.apache.org/repos/asf/webservices/xmlschema/trunk@1560117 13f79535-47bb-0310-9956-ffa450edef68