rpc: increase server_test timeout
rpc: increase server_test timeout

These timeouts are breaking tests in very slow
systems every once in a while.  I've noticed
problems when compiling the Ubuntu packages for
arm, specifically.

R=golang-dev, adg
CC=golang-dev
http://codereview.appspot.com/4291058

rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,Triskite/willstone-goclone,mhennings/marcohennings-go,webfd/go-zh,sanjosh/sanjos100-tipc,npe9/noahevans-go9,webfd/go-zh,scirelli/scirelli-go,Triskite/willstone-goclone,scirelli/scirelli-go,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,d0f/go-zh,npe9/noahevans-go9,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,webfd/go-zh,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,bryanxu/go-zh,bryanxu/go-zh,bryanxu/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,scirelli/scirelli-go,webfd/go-zh,sanjosh/sanjos100-tipc,npe9/noahevans-go9,sanjosh/sanjos100-tipc,npe9/noahevans-go9,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,Triskite/willstone-goclone,bryanxu/go-zh,bryanxu/go-zh,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,rdp/rogerpack2005-golang,npe9/noahevans-go9,rflanagan/reginaldflanagan-project1,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,npe9/noahevans-go9,rdp/rogerpack2005-golang,Triskite/willstone-goclone,d0f/go-zh,scirelli/scirelli-go,bryanxu/go-zh,rdp/rogerpack2005-golang,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,Triskite/willstone-goclone,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,rflanagan/reginaldflanagan-project1,bryanxu/go-zh,d0f/go-zh,Triskite/willstone-goclone,mhennings/marcohennings-go,webfd/go-zh,Triskite/willstone-goclone,glycerine/jeaten-go-arrayof-structof,npe9/noahevans-go9,d0f/go-zh,mhennings/marcohennings-go,webfd/go-zh,rdp/rogerpack2005-golang,scirelli/scirelli-go,glycerine/jeaten-go-arrayof-structof,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,bryanxu/go-zh,Triskite/willstone-goclone,npe9/noahevans-go9,rdp/rogerpack2005-golang,glycerine/jeaten-go-arrayof-structof,d0f/go-zh