Rerun `go generate`. As the diff in zproto-marshal.go shows changing
NotPrimaryMaster.Primary type from NodeID to int8 actually does make a
difference. This happens because NodeID type is based on int32 and
changing that to int8 changes how NotPrimaryMaster structure is layed
out in memory and on the wire.

The changes to zproto-marshal.go in 5d93e434 seem to be done by hand
and not matching the change to proto.go even though head of
zproto-marshal.go says

	// Code generated by protogen.go; DO NOT EDIT.