There are cases of subscriber of a FF publisher not able to lock onto
layer 0 and kept rolling back till it switched to a higher layer and
then it could switch to layer 0. Must have been due to not having a
sender report. Can't think of a reason why that would be missing.
Logging more to debug this further.
Also, using a wrapping logger because of this bug: https://github.com/uber-go/zap/issues/836
Tried using `json:"" yaml:""` tag for `refInfos` field and all fields
inside `refInfo` struct. But, they were still logging nils. So, using
the wrapper logger.
Raja Subramanian
e815c99eac