MB-12067: Enable defragmenter task by default
MB-12067: Enable defragmenter task by default

Change-Id: I7c342aeb306332b7ab389db18f457453c6506e1a
Reviewed-on: http://review.couchbase.org/44423
Reviewed-by: Jim Walker <1cd02e31b43620d7c664e038ca42a060d61727b9@couchbase.com>
Reviewed-by: Chiyoung Seo <fcffc23db27b19ee4ebba46695ee6b50e09216a2@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>
Tested-by: Dave Rigby <a09264da4832c7ff1d3bf1608a19f4b870f93750@couchbase.com>

hisundar/ep-engine,membase/ep-engine,couchbase/ep-engine,teligent-ru/ep-engine,owendCB/ep-engine,couchbase/ep-engine,teligent-ru/ep-engine,daverigby/kv_engine,jimwwalker/ep-engine,sriganes/ep-engine,daverigby/kv_engine,couchbase/ep-engine,daverigby/kv_engine,jimwwalker/ep-engine,daverigby/ep-engine,membase/ep-engine,sriganes/ep-engine,daverigby/ep-engine,daverigby/ep-engine,daverigby/kv_engine,couchbase/ep-engine,teligent-ru/ep-engine,owendCB/ep-engine,hisundar/ep-engine,teligent-ru/ep-engine,membase/ep-engine,sriganes/ep-engine,hisundar/ep-engine,sriganes/ep-engine,hisundar/ep-engine,owendCB/ep-engine,jimwwalker/ep-engine,jimwwalker/ep-engine,daverigby/ep-engine,membase/ep-engine,owendCB/ep-engine