[KYUUBI #1281] [BUG] Prettify error message from engine log.

### _Why are the changes needed?_

Prettify error message from engine log.

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [ ] [Run test](https://kyuubi.readthedocs.io/en/latest/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #1316 from jadireddi/1281-prettyify.

Closes #1281

ae0de364 [Jagadesh Adireddi] [KYUUBI #1281] [BUG] Prettify error message from engine log.

Authored-by: Jagadesh Adireddi <jadiredd@conviva.com>
Signed-off-by: Kent Yao <yao@apache.org>

kyuubi-server/src/main/scala/org/apache/kyuubi/engine/ProcBuilder.scala

@@ -191,7 +191,7 @@ trait ProcBuilder {
     error match {
       case UNCAUGHT_ERROR =>
         KyuubiSQLException(s"Failed to detect the root cause, please check $engineLog at server " +
-          s"side if necessary. The last $engineLogMaxLines line(s) of log is: " +
+          s"side if necessary. The last $engineLogMaxLines line(s) of log are:\n" +
           s"${lastRowsOfLog.toArray.mkString("\n")}")
       case other => other
     }