Add two values for http_proxy to verify that changing it doesn't change any
unexpected tasks.
As this causes uninative to fail to fetch, ensure that uninative is always
disabled.
(From OE-Core rev: 7d8ffd22303a5b89cb129e804c124a2d1dedf9ab)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>