nightly fails rat check down in the dev-support/hbase_nightly_source-artifact.sh check

Nightlies include a nice check that runs through the rc-making steps. See dev-support/hbase_nightly_source-artifact.sh. Currently the nightly is failing here which is causing the nightly runs fail though often enough all tests pass. It looks like cause is the rat check. Unfortunately, running the nightly script locally, all comes up smelling sweet – its a context thing.