Don't run full validation on genesis

grin/src/adapters.rs

@@ -427,7 +427,8 @@ impl NetToChainAdapter {
 		// We are out of consensus at this point and want to track the problem
 		// down as soon as possible.
 		// Skip this if we are currently syncing (too slow).
-		if !self.currently_syncing.load(Ordering::Relaxed)
+		if chain.head().unwrap().height > 0
+			&& !self.currently_syncing.load(Ordering::Relaxed)
 			&& self.config.chain_validation_mode == ChainValidationMode::EveryBlock
 		{
 			let now = Instant::now();