Eventscripts: 10.interface should list configured interfaces

Eventscripts: 10.interface should list configured interfaces

The current code lists available interfaces.  If IPs are configured in
some other way than the public addresses file (e.g. ctdb addip) and their
interfaces default to being marked down then, since down interfaces are
not available, these interfaces can never be marked up.

The configured interfaces should be listed instead.

Signed-off-by: Martin Schwenke <martin@meltin.net>
(This used to be ctdb commit d8f010355b715e49709836e057a5d0f110919897)