format_up doesn't recognise {network_graph_recv} in network module.

[arnaudperalta]

When I use the {network_graph_recv} key in format_up field with the network module, I receive a KeyError in my status bar.
My configuration:

status.register("network",
        format_up="{network_graph_recv}",
        interface="eno1",
        graph_style="blocks"
)

I also got a KeyError when I try to insert the default configuration value from the documentation : {interface} {network_graph_recv}{bytes_recv}KB/s

[terminalmage]

I don't use this module, but it seems like that formatter is only available when network traffic is detected for that interface. The documentation says that you need psutil to get network traffic. Do you have psutil installed?

[arnaudperalta]

I already have psutil installed, this is the exact error I have with the above configuration.