Bump github.com/golang/protobuf from 1.4.2 to 1.4.3

Bumps [github.com/golang/protobuf](https://github.com/golang/protobuf) from 1.4.2 to 1.4.3.
- [Release notes](https://github.com/golang/protobuf/releases)
- [Commits](golang/protobuf@v1.4.2...v1.4.3)

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -5,7 +5,7 @@ go 1.15
 require (
 	github.com/dgryski/go-metro v0.0.0-20200812162917-85c65e2d0165 // indirect
 	github.com/golang/mock v1.4.4
-	github.com/golang/protobuf v1.4.2
+	github.com/golang/protobuf v1.4.3
 	github.com/google/go-cmp v0.5.2
 	github.com/gorilla/websocket v1.4.2
 	github.com/lucas-clemente/quic-go v0.18.1

go.sum

@@ -64,6 +64,8 @@ github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvq
 github.com/golang/protobuf v1.4.1/go.mod h1:U8fpvMrcmy5pZrNK1lt4xCsGvpyWQ/VVv6QDs8UjoX8=
 github.com/golang/protobuf v1.4.2 h1:+Z5KGCizgyZCbGh1KZqA0fcLLkwbsjIzS4aV2v7wJX0=
 github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
+github.com/golang/protobuf v1.4.3 h1:JjCZWpVbqXDqFVmTfYWEVTMIYrL/NPdPSCHPJ0T/raM=
+github.com/golang/protobuf v1.4.3/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=