rebar_xref: ignore opaque type match Dialyzer warning
rebar_xref: ignore opaque type match Dialyzer warning

paulo-ferraz-oliveira/rebar,choptastic/rebar,paulo-ferraz-oliveira/rebar,rebar/rebar,choptastic/rebar,rebar/rebar,paulo-ferraz-oliveira/rebar,apache/couchdb-rebar,apache/couchdb-rebar,choptastic/rebar,apache/couchdb-rebar,rebar/rebar