add reason why this test is @Ignore

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1023265 13f79535-47bb-0310-9956-ffa450edef68

solr/contrib/dataimporthandler/src/test/java/org/apache/solr/handler/dataimport/TestJdbcDataSource.java

@@ -147,7 +147,7 @@ public class TestJdbcDataSource extends AbstractDataImportHandlerTestCase {
   }
 
   @Test
-  @Ignore
+  @Ignore("Needs a Mock database server to work")
   public void testBasic() throws Exception {
     JdbcDataSource dataSource = new JdbcDataSource();
     Properties p = new Properties();