crypto/mime/net/time: add netbsd to +build tags
R=golang-dev, mikioh.mikioh
CC=golang-dev
https://golang.org/cl/5501052
diff --git a/src/pkg/net/ipsock_posix.go b/src/pkg/net/ipsock_posix.go
index f0ca7da..d141c05 100644
--- a/src/pkg/net/ipsock_posix.go
+++ b/src/pkg/net/ipsock_posix.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// +build darwin freebsd linux openbsd windows
+// +build darwin freebsd linux netbsd openbsd windows
package net
