[RDF] Allow "_" to build character token (ROOT-10305).
[RDF] Allow "_" to build character token (ROOT-10305).

karies/root,karies/root,karies/root,karies/root,karies/root,olifre/root,root-mirror/root,karies/root,karies/root,olifre/root,olifre/root,olifre/root,olifre/root,root-mirror/root,olifre/root,olifre/root,olifre/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,karies/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,karies/root,karies/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root