websocket_demo: Use IFF_RUNNING instead of IFF_UP
websocket_demo: Use IFF_RUNNING instead of IFF_UP

When looking for a currently active interface for reporting stats on,
use one that has the IFF_RUNNING flag set and not just IFF_UP. An
interface can have IFF_UP set but not actually be in use. Looking for
IFF_RUNNING seems to produce better results.

Signed-off-by: Andrew Clayton <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@digital-domain.net>

ac000/websocket_demo,ac000/websocket_demo