Fixes more issues swallowing connection errors
Fixes more issues swallowing connection errors

Really need to make sure we are only returning `ErrConnectionFailed`
when it's really a failed connection, not just something that reports as
a non-temporary error.

This fixes more tests on docker CI.

Signed-off-by: Brian Goff <dc73d0991b982a8303e713ef531a313af77e242a@gmail.com>

vdemeester/engine-api,jwhonce/engine-api,docker/engine-api