cbbackupmgr list - JSON unmarshal error on readAnalytics()

Found during performance testing of the list command. Logs show that we receive the following error on running list:

2019-05-24T05:06:52.354-07:00 ERRO: json: Unmarshal(nil *value.Analytics) -- archive.(*bucketDir).readAnalytics() at dir_bucket.go:438

Worth noting that the server isn't running CBAS. 

Logs

6.5.0-3274 (ForestDB)

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-47/leto-srv-01.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-47/leto-srv-02.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-47/leto-srv-03.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-47/leto-srv-04.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-47/tools.zip

6.5.0-3274 (SQLite)

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-48/leto-srv-01.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-48/leto-srv-02.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-48/leto-srv-03.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-48/leto-srv-04.perf.couchbase.com.zip
https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-leto-tmp1-48/tools.zip