uninative: Allow a local own-mirror to work with uninative
The games we play with path manipulation of DL_DIR in uninative mean standard
PREMIRRORS don't work and we can't easily put 'chksum' into the url path from
a url parameter with the current fetcher url handling to make a generic
remapping. We therefore add to PREMIRRORS when we know the chksum to
create a premirror mapping which can work.
[YOCTO #9888]
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
