The original upstream source download url http://download.osgeo.org/
is not stable and sometimes corrupt, so add a mirror from
https://ftp.osuosl.org/ to avoid the do_fetch failure when the
upstream one is corrupted.
Closes-bug: 1954357
Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Change-Id: I307e8a10c85b837081cb3118e619df768f40e385