Fix `line' graph y axis default start point.
Fix `line' graph y axis default start point.

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