panic on GracefulStop with TLS-enabled

[Connor1996]

caused by bug of embed etcd

panic: Drain() is not implemented
goroutine 101105 [running]:
github.com/coreos/etcd/cmd/vendor/google.golang.org/grpc/transport.(*serverHandlerTransport).Drain(0xc4217b18c0)
	/home/gyuho/etcd/release/etcd/gopath/src/github.com/coreos/etcd/cmd/vendor/google.golang.org/grpc/transport/handler_server.go:374 +0x64
github.com/coreos/etcd/cmd/vendor/google.golang.org/grpc.(*Server).GracefulStop(0xc420464620)
	/home/gyuho/etcd/release/etcd/gopath/src/github.com/coreos/etcd/cmd/vendor/google.golang.org/grpc/server.go:1006 +0x2e6
github.com/coreos/etcd/cmd/vendor/github.com/coreos/etcd/embed.(*Etcd).Close.func2(0xc424b04300, 0xc4202f5cc0)
	/home/gyuho/etcd/release/etcd/gopath/src/github.com/coreos/etcd/cmd/vendor/github.com/coreos/etcd/embed/etcd.go:201 +0x54
created by github.com/coreos/etcd/cmd/vendor/github.com/coreos/etcd/embed.(*Etcd).Close
	/home/gyuho/etcd/release/etcd/gopath/src/github.com/coreos/etcd/cmd/vendor/github.com/coreos/etcd/embed/etcd.go:202 +0x20a

[Connor1996]

fix this bug in etcd-io/etcd#8987
update vendor when there is a new release

[disksing]

Please check if this bug is fixed in current master. @Connor1996

[Connor1996]

etcd v3.2.13 has already fixed it. @disksing