* Block announce validation should use the correct `Validation` result
The error variant is just for internal errors and we need to return
`Failure` always when the other node send us an invalid statement.
* Update network/src/lib.rs
Co-authored-by: Sergei Shulepov <sergei@parity.io>
Co-authored-by: Sergei Shulepov <sergei@parity.io>