Fix bug where sensors reports no maximum.
Fix bug where sensors reports no maximum.

fmarchenko/i3pystatus,facetoe/i3pystatus,schroeji/i3pystatus,enkore/i3pystatus,drwahl/i3pystatus,enkore/i3pystatus,Arvedui/i3pystatus,ncoop/i3pystatus,richese/i3pystatus,yang-ling/i3pystatus,teto/i3pystatus,facetoe/i3pystatus,richese/i3pystatus,ncoop/i3pystatus,drwahl/i3pystatus,schroeji/i3pystatus,Arvedui/i3pystatus,yang-ling/i3pystatus,fmarchenko/i3pystatus,teto/i3pystatus