httputil: remove Transport constructors aware of environment

Each of the servers has slightly different needs for configuring their
outbound HTTP transport.  A little copying is better than a little

Notably, the configuration logic in gddo-server is now consistent with
the rest of the configuration-gathering logic.

Change-Id: Ibe7d287a102e20e6e13d97e8a6483d9febab6442
Reviewed-by: Tuo Shan <>
7 files changed