godoc/static/analysis/help.html: fix a typo
godoc/static/analysis/help.html: fix a typo

LGTM=crawshaw, r
R=golang-codereviews, crawshaw, jscrockett01, r
CC=golang-codereviews
https://codereview.appspot.com/110120044

karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools