Use adapter index instead of name for windows IPv6 interface config

Use adapter index instead of name for windows IPv6 interface config

Some windows machines get weird issues with netsh when using
adapter name on "netsh.exe interface ipv6 set address" command.

Changed logic to get adapter index and use it instead of adapter
name for netsh set address command.

v2:
 * Remove netsh call which uses adapter name. After thoughtful testing
   turns out that "adapter name" code branch is never used.

v3:
 * Use interface=<idx> syntax.
 * Add forward declaration of get_adapter_index_flexible to get
   rid of warning.
 * NOTE: temp variable is needed because argv_printf() does not
   handle combined strings like "interface=%lu" today

Signed-off-by: Olli Mannisto <olmannisto@gmail.com>
Signed-off-by: Lev Stipakov <lstipakov@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1447242487-30243-1-git-send-email-lstipakov@gmail.com>
URL: http://article.gmane.org/gmane.network.openvpn.devel/10484
Signed-off-by: Gert Doering <gert@greenie.muc.de>