[release-branch.go1.3] net/http/httptest: disable TestIssue7264

This fails on my OS X machine, just like it did in default branch. In the default branch we removed the test. It's just buggy. LGTM=bradfitz R=bradfitz CC=golang-codereviews https://golang.org/cl/144610043

Author: rsc

src/pkg/net/http/httptest/server_test.go

@@ -30,6 +30,7 @@ func TestServer(t *testing.T) {
 }
 
 func TestIssue7264(t *testing.T) {
+t.Skip("broken test - removed at tip")
 for i := 0; i < 1000; i++ {
 func() {
 inHandler := make(chan bool, 1)