fixed checkstyle

Author: gregw

spring-webflux/src/test/java/org/springframework/web/reactive/function/MultipartRouterFunctionIntegrationTests.java

@@ -49,13 +49,11 @@
 import org.springframework.web.reactive.function.server.ServerRequest;
 import org.springframework.web.reactive.function.server.ServerResponse;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer;
-import org.springframework.web.testfixture.http.server.reactive.bootstrap.JettyCoreHttpServer;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.UndertowHttpServer;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.fail;
 import static org.junit.jupiter.api.Assumptions.assumeFalse;
-import static org.junit.jupiter.api.Assumptions.assumeTrue;
 import static org.springframework.web.reactive.function.server.RouterFunctions.route;
 
 /**