libc/eglibc: Add option that allows for getting svn over http://

Instead of getting eglibc over standard svn://svn.eglibc.org
Add an option that allows the user to get source from
http://www.eglibc.org/svn

This is useful if you are behind a firewall or proxy.
If you are behind a proxy, don't forget to configure
${HOME}/.subversion/servers

In the [global] section setup your proxy configuration.

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
[yann.morin.1998@anciens.enib.fr: removed useless 'default n']
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 mainmenu "The crosstool-NG configuration menu"

 source "config/configure.in"

 source "config/backend.in"

 source "config/global.in"

 source "config/target.in"

 source "config/toolchain.in"

 source "config/kernel.in"

 source "config/binutils.in"

 source "config/cc.in"

 source "config/libc.in"

 source "config/debug.in"

 source "config/companion_libs.in"

 source "config/companion_tools.in"

 source "config/test_suite.in"