Fixed memory leak in testgraph.
Fixed memory leak in testgraph.

libmapper/libmapper,libmapper/libmapper,malloch/libmapper,libmapper/libmapper,radarsat1/libmapper,libmapper/libmapper,libmapper/libmapper,radarsat1/libmapper,radarsat1/libmapper,libmapper/libmapper,radarsat1/libmapper,malloch/libmapper,malloch/libmapper,malloch/libmapper,radarsat1/libmapper,malloch/libmapper,malloch/libmapper