net/http: skip a test on netbsd-arm
net/http: skip a test on netbsd-arm

TestServerDuplicateBackgroundRead has been causing crashes on the
netbsd-arm-bsiegert builder, with the system becoming completely
unresponsive (probably deadlocked). Skip this test while the crash
is under investigation.

Upstream bug report is http://gnats.netbsd.org/53173.

Change-Id: Ib48f19005cf2cbba8a27e75e689c2acb025d8870
Reviewed-on: https://go-review.googlesource.com/106295
Run-TryBot: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>

josharian/go,akutz/go,josharian/go,cloudflare/go,golang/go,cloudflare/go,nawawi/go,nawawi/go,akutz/go,josharian/go,golang/go,cloudflare/go,josharian/go,CAFxX/go,nawawi/go,nawawi/go,cloudflare/go,CAFxX/go,cloudflare/go,golang/go,nawawi/go,nawawi/go,CAFxX/go,golang/go,akutz/go,CAFxX/go,cloudflare/go,josharian/go,golang/go,CAFxX/go,golang/go,cloudflare/go,akutz/go,golang/go,CAFxX/go,golang/go,nawawi/go,josharian/go,akutz/go,akutz/go,cloudflare/go,josharian/go,CAFxX/go,akutz/go,josharian/go,CAFxX/go,nawawi/go,akutz/go