turn-off http2 support

cmd/http/server.go

@@ -194,7 +194,7 @@ func NewServer(addrs []string, handler http.Handler, getCert certs.GetCertificat
 			// TLS hardening
 			PreferServerCipherSuites: true,
 			MinVersion:               tls.VersionTLS12,
-			NextProtos:               []string{"h2", "http/1.1"},
+			NextProtos:               []string{"http/1.1", "h2"},
 		}
 		tlsConfig.GetCertificate = getCert
 	}

cmd/utils.go

@@ -45,7 +45,6 @@ import (
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/handlers"
 	"github.com/minio/minio/pkg/madmin"
-	"golang.org/x/net/http2"
 )
 
 const (
@@ -481,10 +480,6 @@ func newInternodeHTTPTransport(tlsConfig *tls.Config, dialTimeout time.Duration)
 		DisableCompression: true,
 	}
 
-	if tlsConfig != nil {
-		http2.ConfigureTransport(tr)
-	}
-
 	return func() *http.Transport {
 		return tr
 	}
@@ -532,10 +527,6 @@ func newCustomHTTPTransport(tlsConfig *tls.Config, dialTimeout time.Duration) fu
 		DisableCompression: true,
 	}
 
-	if tlsConfig != nil {
-		http2.ConfigureTransport(tr)
-	}
-
 	return func() *http.Transport {
 		return tr
 	}