message: chore: Turn chain service channel panic into an error
diff: @@ -50,7 +50,7 @@ impl ChainController {
  need_verify: bool,
  ) -> Result<bool, FailureError> {
  Request::call(&self.process_block_sender, (block, need_verify))
  - .expect("process_block() failed")
  + .unwrap_or_else(|| Err(failure::err_msg("Chain service has gone")))
  }
  }
  