Update module github.com/deepch/vdk to v0.0.21

Generated by renovateBot

Author: renovate[bot]

go.mod

@@ -3,7 +3,7 @@ module github.com/pion/rtsp-bench
 go 1.12
 
 require (
-	github.com/deepch/vdk v0.0.0-20211113104208-022deeb641f7
+	github.com/deepch/vdk v0.0.21
 	github.com/pion/webrtc/v3 v3.1.1
 	github.com/shirou/gopsutil v3.22.2+incompatible
 	github.com/tklauser/go-sysconf v0.3.9 // indirect