net: increase TestNotTemporaryRead server sleep
net: increase TestNotTemporaryRead server sleep

On aix/ppc64, if the server closes before the client calls Accept,
this test will fail.

Increasing the time before the server closes should resolve this
timeout.

Updates #29685

Change-Id: Iebb849d694fc9c37cf216ce1f0b8741249b98016
Reviewed-on: https://go-review.googlesource.com/c/158038
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

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