net/http: remove an errant space
net/http: remove an errant space

Made the godoc overview section oddly indented
compared to the other code blocks.

R=golang-dev, mikioh.mikioh, dsymonds, r
CC=golang-dev
http://codereview.appspot.com/5645060

webfd/go-zh,mhennings/marcohennings-go,bryanxu/go-zh,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,scirelli/scirelli-go,Triskite/willstone-goclone,scirelli/scirelli-go,Triskite/willstone-goclone,rdp/rogerpack2005-golang,d0f/go-zh,rdp/rogerpack2005-golang,bryanxu/go-zh,rdp/rogerpack2005-golang,Triskite/willstone-goclone,scirelli/scirelli-go,rflanagan/reginaldflanagan-project1,webfd/go-zh,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,d0f/go-zh,d0f/go-zh,Triskite/willstone-goclone,rflanagan/reginaldflanagan-project1,Triskite/willstone-goclone,webfd/go-zh,scirelli/scirelli-go,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,d0f/go-zh,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,rdp/rogerpack2005-golang,mhennings/marcohennings-go,bryanxu/go-zh,mhennings/marcohennings-go,bryanxu/go-zh,sanjosh/sanjos100-tipc,scirelli/scirelli-go,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,scirelli/scirelli-go,d0f/go-zh,webfd/go-zh,mhennings/marcohennings-go,scirelli/scirelli-go,d0f/go-zh,sanjosh/sanjos100-tipc,Triskite/willstone-goclone,Triskite/willstone-goclone,Triskite/willstone-goclone,webfd/go-zh,rflanagan/reginaldflanagan-project1,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,d0f/go-zh,d0f/go-zh,glycerine/jeaten-go-arrayof-structof,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,rflanagan/reginaldflanagan-project1