Fix issue when adding metric to a graph.
Fix issue when adding metric to a graph.

facette/facette,facette/facette,facette/facette,vovkasm/facette,Skrupellos/facette,psytra/facette,hirocaster/facette,psytra/facette,yonglehou/facette,vovkasm/facette,vovkasm/facette,iaean/facette,facette/facette,githubert/facette,hirocaster/facette,iaean/facette,yonglehou/facette,iaean/facette,githubert/facette,yonglehou/facette,Skrupellos/facette,psytra/facette,Skrupellos/facette,githubert/facette,hirocaster/facette