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>
(transplanted from cb75966698d7e44bc76445d7b249eba89bdf1d8a)

 python

 import sys

 sys.path.insert(0, '@@PREFIX@@/share/gcc-@@VERSION@@/python')

 from libstdcxx.v6.printers import register_libstdcxx_printers

 register_libstdcxx_printers (None)

 end