libnet/d/bridge: remove dead ActiveEndpointsError

This error is unused since docker/libnetwork@6b158eac6.

Signed-off-by: Albin Kerouanton <albinker@gmail.com>

libnetwork/drivers/bridge/errors.go

@@ -104,17 +104,6 @@ func (uat ErrUnsupportedAddressType) Error() string {
 // InvalidParameter denotes the type of this error
 func (uat ErrUnsupportedAddressType) InvalidParameter() {}
 
-// ActiveEndpointsError is returned when there are
-// still active endpoints in the network being deleted.
-type ActiveEndpointsError string
-
-func (aee ActiveEndpointsError) Error() string {
-	return fmt.Sprintf("network %s has active endpoint", string(aee))
-}
-
-// Forbidden denotes the type of this error
-func (aee ActiveEndpointsError) Forbidden() {}
-
 // InvalidNetworkIDError is returned when the passed
 // network id for an existing network is not a known id.
 type InvalidNetworkIDError string