remove extra aware interface (#2636)

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignClientsRegistrar.java

@@ -60,15 +60,13 @@ import org.springframework.util.StringUtils;
  * @author Gang Li
  */
 class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar,
-		ResourceLoaderAware, BeanClassLoaderAware, EnvironmentAware {
+		ResourceLoaderAware, EnvironmentAware {
 
 	// patterned after Spring Integration IntegrationComponentScanRegistrar
 	// and RibbonClientsConfigurationRegistgrar
 
 	private ResourceLoader resourceLoader;
 
-	private ClassLoader classLoader;
-
 	private Environment environment;
 
 	public FeignClientsRegistrar() {
@@ -79,11 +77,6 @@ class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar,
 		this.resourceLoader = resourceLoader;
 	}
 
-	@Override
-	public void setBeanClassLoader(ClassLoader classLoader) {
-		this.classLoader = classLoader;
-	}
-
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata metadata,
 			BeanDefinitionRegistry registry) {
@@ -386,8 +379,7 @@ class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar,
 		 * @param delegates must not be {@literal null}.
 		 */
 		public AllTypeFilter(List<TypeFilter> delegates) {
-
-			Assert.notNull(delegates);
+			Assert.notNull(delegates, "This argument is required, it must not be null");
 			this.delegates = delegates;
 		}