Display mode fails to change to graph if a filter is not defined

[spacez320]

Run something like:

shui --query 'uptime | awk '\''{print $9}'\'' | tr -d ","' --expr 'get(result, "0") * 100' --display 3 --count -1 without --filters and then attempt to TAB into the fourth display mode, which right now throws an exit.

It could be the case that it isn't the absence of --filters, but it seems likely.