scripts: use generic urls for sourceforge

For expat, duma, and strace, use the generic url and 302 to the mirror
instead of trying to download a file from a downed mirror and
failing.

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
Message-Id: <b69ebeb72fef93c04c84.1345364051@flambe.is-a-geek.org>

# Compute s390-specific values

CT_DoArchTupleValues() {

    # That's the only thing to override

    if [ "${CT_ARCH_64}" = "y" ]; then

        CT_TARGET_ARCH="s390x"

    fi

}