cmd/go/internal/modfetch: more logging in TestConvertLegacyConfig
cmd/go/internal/modfetch: more logging in TestConvertLegacyConfig

Make the test report git commands run when invoked with -v
(by setting the build -x flag).

Change-Id: I83a532a491eba3b5e330d37897d563e394950641
Reviewed-on: https://go-review.googlesource.com/117937
Run-TryBot: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
Reviewed-by: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>

golang/vgo,golang/vgo