package: use http:// for alioth.debian.org URLs

Fixes http://autobuild.buildroot.net/results/183a1be6ab1137c90dca0201d4bc72c7c0e659a3



alioth.debian.org uses a SSL certificate signed by spi-inc.org, which isn't
a trusted CA on non-Debian systems, causing wget to refuse download.

Fix it by using http URLs instead.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>