doc/go1.3.html: fix typo
doc/go1.3.html: fix typo

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://codereview.appspot.com/92440043

webfd/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,webfd/go-zh,sanjosh/sanjos100-tipc,bryanxu/go-zh,bryanxu/go-zh,sanjosh/sanjos100-tipc,sanjosh/sanjos100-tipc,bryanxu/go-zh,bryanxu/go-zh,bryanxu/go-zh,bryanxu/go-zh,d0f/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,webfd/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,webfd/go-zh,webfd/go-zh,sanjosh/sanjos100-tipc,d0f/go-zh,d0f/go-zh,webfd/go-zh,webfd/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,d0f/go-zh,bryanxu/go-zh,bryanxu/go-zh,webfd/go-zh