test/fixedbugs: bump issue21576.go's timeout to 1min
test/fixedbugs: bump issue21576.go's timeout to 1min

Increases the exec timeout from 5sec to 1min, but
also print out the error value on any test failure.

Fixes #34836

Change-Id: Ida2b8bd460243491ef0f90dfe0f978dfe02a0703
Reviewed-on: https://go-review.googlesource.com/c/go/+/200519
Run-TryBot: Emmanuel Odeke <277f8eaa8c7dfbc55c17bf5e30561c1a9c45c569@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>

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