panic: runtime error: invalid memory address or nil pointer dereference

[cos800]

运行一段时间，就崩了。。。

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x5375b6]

goroutine 449 [running]:
bufio.(*Writer).Flush(0xc0001fbb40)
	/usr/local/go/src/bufio/bufio.go:628 +0x56
bufio.(*Writer).Write(0xc0001fbb40, {0xc0006221a3?, 0x436dd2?, 0xc000214110?})
	/usr/local/go/src/bufio/bufio.go:672 +0xd8
net/http.(*response).write(0xc0000ba0e0, 0xbd, {0xc0006221a3, 0xbd, 0x56e5d}, {0x0, 0x0})
	/usr/local/go/src/net/http/server.go:1615 +0x21e
net/http.(*response).Write(0xc00023e010?, {0xc0006221a3?, 0x7ce8f?, 0xc00003ef03?})
	/usr/local/go/src/net/http/server.go:1573 +0x30
github.com/gwuhaolin/livego/protocol/httpflv.(*FLVWriter).SendPacket(0xc00023e000)
	/mnt/c/Users/cosx/dev/livego/protocol/httpflv/writer.go:151 +0x1d3
github.com/gwuhaolin/livego/protocol/httpflv.NewFLVWriter.func1()
	/mnt/c/Users/cosx/dev/livego/protocol/httpflv/writer.go:55 +0x26
created by github.com/gwuhaolin/livego/protocol/httpflv.NewFLVWriter
	/mnt/c/Users/cosx/dev/livego/protocol/httpflv/writer.go:54 +0x42a