MIRRORS needs to be pairs of values for the original URL to match and the
location find it on the mirror.
(From OE-Core rev: a649f3da630e8ca2d3ca58b610f3918720dd5229)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>