scripts: do not download in // by default

Parallel downloads can be a bit harsh on the servers,
and some will fail (eg. uclibc.org) in some cases.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

reporter_name="Harold Grovesteen"

reporter_url="http://sourceware.org/ml/crossgcc/2009-11/msg00052.html"

reporter_comment=""