vendor: github.com/docker/docker 2269acc7a31d (master, v-next)

removes (indirect) dependencie on the moby/sys/user/userns package, which
was retracted and moved to moby/sys/userns

- full diff: f3cf9359bd...2269acc7a3

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/docker/docker/pkg/archive/archive_linux.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/docker/docker/pkg/system"
-	"github.com/moby/sys/user/userns"
+	"github.com/moby/sys/userns"
 	"github.com/pkg/errors"
 	"golang.org/x/sys/unix"
 )