Fix make distcheck by adding a missing file to Makefile.am.
Fix make distcheck by adding a missing file to Makefile.am.

andyflury/opentsdb,alienth/opentsdb,kidaa/opentsdb,OpenTSDB/opentsdb,sidhhu/opentsdb,MadDogTechnology/opentsdb,sidhhu/opentsdb,kidaa/opentsdb,johann8384/opentsdb,alienth/opentsdb,eswdd/opentsdb,OpenTSDB/opentsdb,eswdd/opentsdb,MadDogTechnology/opentsdb,MadDogTechnology/opentsdb,OpenTSDB/opentsdb,ShefronYudy/opentsdb,andyflury/opentsdb,johann8384/opentsdb,ShefronYudy/opentsdb