Remove unused code

spring-web/src/main/java/org/springframework/web/accept/ContentNegotiationManagerFactoryBean.java

@@ -190,10 +190,6 @@ public class ContentNegotiationManagerFactoryBean implements FactoryBean<Content
 		this.useRegisteredExtensionsOnly = useRegisteredExtensionsOnly;
 	}
 
-	private boolean useRegisteredExtensionsOnly() {
-		return (this.useRegisteredExtensionsOnly != null && this.useRegisteredExtensionsOnly);
-	}
-
 	/**
 	 * Whether to disable checking the 'Accept' request header.
 	 * <p>By default this value is set to {@code false}.

spring-webmvc/src/test/java/org/springframework/web/servlet/config/MvcNamespaceTests.java

@@ -389,9 +389,6 @@ public class MvcNamespaceTests {
 		HttpRequestHandlerAdapter adapter = appContext.getBean(HttpRequestHandlerAdapter.class);
 		assertThat(adapter).isNotNull();
 
-		RequestMappingHandlerMapping mapping = appContext.getBean(RequestMappingHandlerMapping.class);
-		ContentNegotiationManager manager = mapping.getContentNegotiationManager();
-
 		SimpleUrlHandlerMapping resourceMapping = appContext.getBean(SimpleUrlHandlerMapping.class);
 		assertThat(resourceMapping).isNotNull();
 		assertThat(resourceMapping.getOrder()).isEqualTo(Ordered.LOWEST_PRECEDENCE - 1);