[SANTUARIO-399] - XMLCipher fails to declare signature namespace on xenc:EncryptionMethod/ds:DigestMethod elements

git-svn-id: https://svn.apache.org/repos/asf/santuario/xml-security-java/branches/1.5.x-fixes@1626705 13f79535-47bb-0310-9956-ffa450edef68