HBASE-23053 Disable concurrent nightly builds (#654)
HBASE-23053 Disable concurrent nightly builds (#654)

Signed-off-by: Sean Busbey <5c0191c5bda2836af1cb87878694cfbf1db676c8@apache.org>
mahak/hbase,ChinmaySKulkarni/hbase,ndimiduk/hbase,francisliu/hbase,ChinmaySKulkarni/hbase,francisliu/hbase,ChinmaySKulkarni/hbase,apurtell/hbase,apurtell/hbase,apurtell/hbase,francisliu/hbase,apurtell/hbase,apurtell/hbase,francisliu/hbase,Apache9/hbase,Apache9/hbase,francisliu/hbase,mahak/hbase,mahak/hbase,Apache9/hbase,ndimiduk/hbase,Apache9/hbase,apurtell/hbase,francisliu/hbase,ndimiduk/hbase,ChinmaySKulkarni/hbase,mahak/hbase,ChinmaySKulkarni/hbase,apurtell/hbase,ndimiduk/hbase,Apache9/hbase,ndimiduk/hbase,francisliu/hbase,apurtell/hbase,ChinmaySKulkarni/hbase,ndimiduk/hbase,mahak/hbase,apurtell/hbase,mahak/hbase,Apache9/hbase,ndimiduk/hbase,ndimiduk/hbase,ChinmaySKulkarni/hbase,mahak/hbase,francisliu/hbase,mahak/hbase,Apache9/hbase,Apache9/hbase,Apache9/hbase,apurtell/hbase,ChinmaySKulkarni/hbase,ndimiduk/hbase,francisliu/hbase,ndimiduk/hbase,mahak/hbase,ChinmaySKulkarni/hbase,Apache9/hbase,mahak/hbase,francisliu/hbase,ChinmaySKulkarni/hbase