Fix checkstyle violation

Author: rstoyanchev

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

@@ -20,8 +20,6 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.function.Consumer;
 import java.util.function.Predicate;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -38,8 +36,6 @@
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
-import org.springframework.http.codec.FormHttpMessageReader;
-import org.springframework.http.codec.FormHttpMessageWriter;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;