net/http/httptrace: fix typo
net/http/httptrace: fix typo

Change-Id: I15279e4aa9306bde925929907a7b5e7ef5d8b642
GitHub-Last-Rev: 6bc2d66aecd424b322ec0c23b280e74cb22e08c3
GitHub-Pull-Request: golang/go#30193
Reviewed-on: https://go-review.googlesource.com/c/162018
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

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