fix: fix npe when add circuitbreak module without feign.hystrix.enable=true

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

@@ -113,10 +113,11 @@ public class PolarisFeignCircuitBreakerInvocationHandler implements InvocationHa
 		else if ("toString".equals(method.getName())) {
 			return toString();
 		}
-
+		Supplier<Object> supplier = asSupplier(method, args);
+		if (circuitBreakerNameResolver != null) {
 			String circuitName = circuitBreakerNameResolver.resolveCircuitBreakerName(feignClientName, target, method);
 			CircuitBreaker circuitBreaker = factory.create(circuitName);
-		Supplier<Object> supplier = asSupplier(method, args);
+
 			Function<Throwable, Object> fallbackFunction;
 			if (this.nullableFallbackFactory != null) {
 				fallbackFunction = throwable -> {
@@ -145,6 +146,10 @@ public class PolarisFeignCircuitBreakerInvocationHandler implements InvocationHa
 				throw e.getCause();
 			}
 		}
+		else {
+			return supplier.get();
+		}
+	}
 
 	private void unwrapAndRethrow(Exception exception) {
 		if (exception instanceof InvocationTargetException || exception instanceof NoFallbackAvailableException) {