meshstats: don't count undefined as gateway
meshstats: don't count undefined as gateway

plumpudding/hopglass,Freifunk-Luxembourg/hopglass,Freifunk-Luxembourg/hopglass,yayachiken/hopglass,srauscher/hopglass,gherber/hopglass,srauscher/hopglass,hopglass/hopglass,hopglass/hopglass,yayachiken/hopglass,gherber/hopglass,plumpudding/hopglass