Fix print statement in backend
Fix print statement in backend

PingThingsIO/pt-mr-plotter,SoftwareDefinedBuildings/mr-plotter,SoftwareDefinedBuildings/mr-plotter,PingThingsIO/pt-mr-plotter,SoftwareDefinedBuildings/mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,SoftwareDefinedBuildings/mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,SoftwareDefinedBuildings/mr-plotter,SoftwareDefinedBuildings/mr-plotter