test: mask 'nil Context' for staticcheck
test: mask 'nil Context' for staticcheck

Signed-off-by: Gyu-Ho Lee <3454051ee3341eb69bdf6fca40899cdad4d86496@gmail.com>

gyuho/etcd,dannysauer/etcd,cockroachdb/etcd,glevand/coreos--etcd,coreos/etcd,mkumatag/etcd,a-robinson/etcd,mqliang/etcd,sinsharat/etcd,dannysauer/etcd,etcd-io/etcd,joshix/etcd,xiang90/etcd,coreos/etcd,bdarnell/etcd,bluebreezecf/etcd,rnaveiras/etcd,lorneli/etcd,etcd-io/etcd,YuleiXiao/etcd,mqliang/etcd,cockroachdb/etcd,glevand/coreos--etcd,li-ang/etcd,fanminshi/etcd,rnaveiras/etcd,etcd-io/etcd,fanminshi/etcd,joshix/etcd,mkumatag/etcd,heyitsanthony/etcd,bdarnell/etcd,mickep76/etcd,YuleiXiao/etcd,heyitsanthony/etcd,visheshnp/etcd,li-ang/etcd,rnaveiras/etcd,mkumatag/etcd,vimalk78/etcd,sebrandon1/etcd,whuwxl/etcd,vimalk78/etcd,ajityagaty/etcd,ajityagaty/etcd,mqliang/etcd,gyuho/etcd,lorneli/etcd,sebrandon1/etcd,akauppi/etcd,mickep76/etcd,xiang90/etcd,ajityagaty/etcd,whuwxl/etcd,a-robinson/etcd,akauppi/etcd,sinsharat/etcd,visheshnp/etcd,bluebreezecf/etcd