doc: update links in contribute.html
CLA links are now redirects. Use new URLs instead. Also, use https:// links for all Google sites where the http version just redirects to https anyway. (That's all links on the page, as it turns out) LGTM=adg R=golang-codereviews, adg CC=golang-codereviews https://golang.org/cl/69980051
Showing
Please
register
or
sign in
to comment