Revert "set http.Client.Timeout in net2/http2.SimplePool if supported (>= go-1.3)"

This reverts commit 02ef46632aff5043f912d3eb40ccdf9b65cff691.
Merge pull request #70 from mallipeddi/http-client-timeout

Revert "set http.Client.Timeout in net2/http2.SimplePool if supported (>...