IGNITE-6826 is ready for review (Change default DiscoverySpi ipFinder type for examples)

[Dmitrii Ryabov]

Hello Igniters!
I’ve changed default ipFinder in examples from multicast to static, so
examples will run faster.
Please, review.

JIRA: https://issues.apache.org/jira/browse/IGNITE-6826
GitHub: https://github.com/apache/ignite/pull/3362
Upsource: https://reviews.ignite.apache.org/ignite/review/IGNT-CR-454