Replace "blacklist" with alternative words

See gh-25262

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/CrossOriginAnnotationIntegrationTests.java

@@ -76,7 +76,7 @@ class CrossOriginAnnotationIntegrationTests extends AbstractRequestMappingIntegr
 
 	@Override
 	protected RestTemplate initRestTemplate() {
-		// JDK default HTTP client blacklist headers like Origin
+		// JDK default HTTP client disallowed headers like Origin
 		return new RestTemplate(new HttpComponentsClientHttpRequestFactory());
 	}
 

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/GlobalCorsConfigIntegrationTests.java

@@ -64,7 +64,7 @@ class GlobalCorsConfigIntegrationTests extends AbstractRequestMappingIntegration
 
 	@Override
 	protected RestTemplate initRestTemplate() {
-		// JDK default HTTP client blacklists headers like Origin
+		// JDK default HTTP client disallowed headers like Origin
 		return new RestTemplate(new HttpComponentsClientHttpRequestFactory());
 	}