core,eth,light: fix errors in the function GetBlockNumber caused by u… #416

Job	Run time
tests (A-B tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFinOrg/...	1m 30s
tests (C-[a-m] tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFin...	1m 56s
tests (C-[n-o] tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFin...	7m 24s
tests (C-[p-z] tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFin...	32s
tests (D-I tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFinOrg/...	2m 38s
tests (J-N tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFinOrg/...	2m 14s
tests (O-S tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFinOrg/...	1m 26s
tests (T-Z tests, go run build/ci.go test -coverage $(go list ./... \| grep "github.com/XinFinOrg/...	1m 1s
tag_build	0s
devnet_build_push	0s
devnet_k8_apply	0s
rpcnode_terraform_apply	0s
rpc_k8_apply	0s
	18m 41s

Provide feedback