Make sure the wg interface is down when created

Author: dtoubelis

src/link/add.rs

@@ -756,7 +756,9 @@ impl LinkAddRequest {
     /// Create a wireguard link.
     /// This is equivalent to `ip link add NAME type wireguard`.
     pub fn wireguard(self, name: String) -> Self {
-        self.name(name).link_info(InfoKind::Wireguard, None)
+        let mut request = self.name(name).link_info(InfoKind::Wireguard, None);
+        request.message_mut().header.flags &= !IFF_UP;
+        request
     }
 
     /// Replace existing matching link.