If the opkg/apt tests are run without a package-index they will fail.
Trigger this here for now as a dependency until the code can be improved.
(From OE-Core rev: 7805eec0f522da2d2b6a08c8a07a9243e26c014a)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>