use only 5** as default err in scg

spring-cloud-starter-tencent-polaris-circuitbreaker/src/main/java/com/tencent/cloud/polaris/circuitbreaker/feign/PolarisFeignCircuitBreaker.java

@@ -25,7 +25,7 @@ import org.springframework.cloud.openfeign.CircuitBreakerNameResolver;
 import org.springframework.cloud.openfeign.FallbackFactory;
 
 /**
- * PolarisFeignCircuitBreaker, mostly copy from FeignCircuitBreaker, but giving Polaris modification.
+ * PolarisFeignCircuitBreaker, mostly copy from {@link org.springframework.cloud.openfeign.FeignCircuitBreaker}, but giving Polaris modification.
  *
  * @author sean yu
  */

spring-cloud-starter-tencent-polaris-circuitbreaker/src/main/java/com/tencent/cloud/polaris/circuitbreaker/feign/PolarisFeignCircuitBreakerInvocationHandler.java

@@ -41,7 +41,7 @@ import org.springframework.web.context.request.RequestContextHolder;
 import static feign.Util.checkNotNull;
 
 /**
- * PolarisFeignCircuitBreakerInvocationHandler, mostly copy from FeignCircuitBreakerInvocationHandler, but giving Polaris modification.
+ * PolarisFeignCircuitBreakerInvocationHandler, mostly copy from {@link org.springframework.cloud.openfeign.FeignCircuitBreakerInvocationHandler}, but giving Polaris modification.
  *
  * @author sean yu
  */

spring-cloud-starter-tencent-polaris-circuitbreaker/src/main/java/com/tencent/cloud/polaris/circuitbreaker/feign/PolarisFeignCircuitBreakerTargeter.java

@@ -29,7 +29,7 @@ import org.springframework.cloud.openfeign.Targeter;
 import org.springframework.util.StringUtils;
 
 /**
- * PolarisFeignCircuitBreakerTargeter, mostly copy from FeignCircuitBreakerTargeter, but giving Polaris modification.
+ * PolarisFeignCircuitBreakerTargeter, mostly copy from {@link org.springframework.cloud.openfeign.FeignCircuitBreakerTargeter}, but giving Polaris modification.
  *
  * @author sean yu
  */

spring-cloud-starter-tencent-polaris-circuitbreaker/src/main/java/com/tencent/cloud/polaris/circuitbreaker/gateway/PolarisCircuitBreakerFilterFactory.java

@@ -157,7 +157,7 @@ public class PolarisCircuitBreakerFilterFactory extends SpringCloudCircuitBreake
 
 	private Set<HttpStatus> getDefaultStatus() {
 		return Arrays.stream(HttpStatus.values())
-				.filter(status -> status.is4xxClientError() || status.is5xxServerError())
+				.filter(HttpStatus::is5xxServerError)
 				.collect(Collectors.toSet());
 	}