(IGNITE-5695) FlinkIgniteSinkSelfTest is failing due to conflicting default test timeout and default flush frequency

[Saikat Maitra]

Hi,

I have raised a PR to address the failing test FlinkIgniteSinkSelfTest due
to same timeout settings for test and data flush frequency.

Please review and let me know feedback.

jira - https://issues.apache.org/jira/browse/IGNITE-5695
PR - https://github.com/apache/ignite/pull/2241

Regards,
Saikat