Fix #679 where an NPE is thrown if the logback config doesn't have a cyclic buffered appender to keep track of the last x log lines. Now it will throw a BadRequest exception with a useful message.
Fix #679 where an NPE is thrown if the logback config doesn't have
a cyclic buffered appender to keep track of the last x log lines.
Now it will throw a BadRequest exception with a useful message.

Signed-off-by: Chris Larsen <83037b211e1d109d6858769a113e269c3139ffd3@yahoo-inc.com>

alienth/opentsdb,OpenTSDB/opentsdb,eswdd/opentsdb,OpenTSDB/opentsdb,MadDogTechnology/opentsdb,OpenTSDB/opentsdb,alienth/opentsdb,MadDogTechnology/opentsdb,eswdd/opentsdb,MadDogTechnology/opentsdb