Remove unused import

See gh-28223

Author: scottfrederick

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java

@@ -32,7 +32,6 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 
-import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.validation.ValidatorFactory;