MB-100: unbreak dialyzer breakage

Change-Id: I4fce022a53a4f54ce7534cffb4554ed2d8708e77
Reviewed-on: http://review.couchbase.org/28262
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>