Automatic merge from submit-queue (batch tested with PRs 37677, 38519)

Better deal with failures under golang 1.8beta1

If there is any error in the initial parsing then we should just
try adding the scheme.

url.Parse(base) has changed in 1.8. Please see the following change
https://github.com/golang/go/commit/c5ccbdd22bdbdc43d541b7e7d4ed66ceb559030e

Fixes #38380