Uses the HTTPS url for cases where the existing URL has a permanent
redirect. For each domain, at least one fixed derivation URL was
downloaded to test the domain is properly serving downloads.
Also fixes jbake source URL, which was broken.
Missing quotes of $UNAME_CMD in the firehol bash script
result in an error if the path to uname contains a dash,
as in /nix/store/...-coreutils-.../bin/uname.
Might be considered an upstream bug but only appears
in this special case, unlikely to occur in other distros.
