Remove msgp workaround (#10964)

The error in `github.com/philhofer/fwd` was quickly fixed through 
https://github.com/philhofer/fwd/pull/22 - update the dependency 
and remove the workaround.

cmd/metacache-stream.go

@@ -247,9 +247,7 @@ type metacacheReader struct {
 func newMetacacheReader(r io.Reader) (*metacacheReader, error) {
 	dec := s2DecPool.Get().(*s2.Reader)
 	dec.Reset(r)
-	// TODO: Go back to default size when this fix is available:
-	// https://github.com/philhofer/fwd/issues/20
-	mr := msgp.NewReaderSize(dec, 64<<10)
+	mr := msgp.NewReader(dec)
 	m := metacacheReader{
 		mr: mr,
 		closer: func() {

go.mod

@@ -62,7 +62,7 @@ require (
 	github.com/nats-io/stan.go v0.7.0
 	github.com/ncw/directio v1.0.5
 	github.com/nsqio/go-nsq v1.0.7
-	github.com/philhofer/fwd v1.1.0 // indirect
+	github.com/philhofer/fwd v1.1.1 // indirect
 	github.com/pierrec/lz4 v2.4.0+incompatible
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.0.0

go.sum

@@ -379,6 +379,8 @@ github.com/pascaldekloe/goe v0.1.0/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144T
 github.com/pborman/getopt v0.0.0-20180729010549-6fdd0a2c7117/go.mod h1:85jBQOZwpVEaDAr341tbn15RS4fCAsIst0qp7i8ex1o=
 github.com/philhofer/fwd v1.1.0 h1:PAdZw9+/BCf4gc/kA2L/PbGPkFe72Kl2GLZXTG8HpU8=
 github.com/philhofer/fwd v1.1.0/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
+github.com/philhofer/fwd v1.1.1 h1:GdGcTjf5RNAxwS4QLsiMzJYj5KEvPJD3Abr261yRQXQ=
+github.com/philhofer/fwd v1.1.1/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
 github.com/pierrec/lz4 v2.0.5+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pierrec/lz4 v2.2.6+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pierrec/lz4 v2.4.0+incompatible h1:06usnXXDNcPvCHDkmPpkidf4jTc52UKld7UPfqKatY4=