Correct omitted Label element declaration in ccnx.dtd.  Refs #100371
Correct omitted Label element declaration in ccnx.dtd.  Refs #100371

ebollens/ccnmp,cawka/ndnx,svartika/ccnx,svartika/ccnx,ebollens/ccnmp,svartika/ccnx,svartika/ccnx,ebollens/ccnmp,svartika/ccnx,cawka/ndnx,svartika/ccnx,ebollens/ccnmp,cawka/ndnx,svartika/ccnx,cawka/ndnx,cawka/ndnx