Fix using wrong value (dumb mistake) in mval_add_to_message().
Fix using wrong value (dumb mistake) in mval_add_to_message().

johnty/libmapper,radarsat1/libmapper,johnty/libmapper,radarsat1/libmapper,libmapper/libmapper,libmapper/libmapper,davidhernon/libmapper,davidhernon/libmapper-admin2,malloch/libmapper,johnty/libmapper,davidhernon/libmapper-admin2,libmapper/libmapper,malloch/libmapper,davidhernon/libmapper-admin2,libmapper/libmapper,malloch/libmapper,johnty/libmapper,davidhernon/libmapper,malloch/libmapper,johnty/libmapper,davidhernon/libmapper,radarsat1/libmapper,radarsat1/libmapper,davidhernon/libmapper,davidhernon/libmapper,libmapper/libmapper,davidhernon/libmapper-admin2,malloch/libmapper,davidhernon/libmapper-admin2,libmapper/libmapper,radarsat1/libmapper,malloch/libmapper