f add height compare check

Author: TheBlueMatt

lightning/src/chain/chainmonitor.rs

@@ -264,7 +264,7 @@ where C::Target: chain::Filter,
 			// Sadly AtomicUsize::fetch_max wasn't stabilized until 1.45, so until then we have to
 			// manually CAS.
 			let mut old_height = self.highest_chain_height.load(Ordering::Relaxed);
-			while self.highest_chain_height
+			while height as usize > old_height && self.highest_chain_height
 				.compare_exchange(old_height, height as usize, Ordering::AcqRel, Ordering::Relaxed).is_err()
 			{
 				old_height = self.highest_chain_height.load(Ordering::Acquire);