add instanceof

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

@@ -53,8 +53,11 @@ public class PolarisRestTemplateRegisterAutoConfiguration implements Application
 	}
 
 	private void initRestTemplate(String beanName, Object bean) {
-		RestTemplate restTemplate = (RestTemplate) bean;
+		if (bean instanceof RestTemplate) {
-		restTemplate.setErrorHandler(polarisRestTemplateResponseErrorHandler);
+			RestTemplate restTemplate = (RestTemplate) bean;
+			restTemplate.setErrorHandler(polarisRestTemplateResponseErrorHandler);
+		}
+		
 	}
 
 	@Override