fix checkstyle

test/src/test/java/org/springframework/security/test/web/servlet/setup/SecurityMockMvcConfigurerTests.java

@@ -27,8 +27,6 @@ import org.springframework.web.context.WebApplicationContext;
 
 import javax.servlet.Filter;
 import javax.servlet.ServletContext;
-import javax.servlet.ServletException;
-import java.io.IOException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.anyString;