Removed unused import. [ci skip]

Author: harawata

src/test/java/org/apache/ibatis/submitted/ancestor_ref/AncestorRefTest.java

@@ -26,7 +26,6 @@
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 import org.junit.BeforeClass;
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class AncestorRefTest {