Update vendoring via vndr

gateway/vendor/github.com/docker/go-connections/tlsconfig/certpool_other.go

@@ -5,12 +5,10 @@ package tlsconfig
 import (
 	"crypto/x509"
 
-	"github.com/Sirupsen/logrus"
 )
 
 // SystemCertPool returns an new empty cert pool,
 // accessing system cert pool is supported in go 1.7
 func SystemCertPool() (*x509.CertPool, error) {
-	logrus.Warn("Unable to use system certificate pool: requires building with go 1.7 or later")
 	return x509.NewCertPool(), nil
 }