Upgrading H2 to latest version.

After setting up a automated test workflow, we ran into a bug with H2. It appears the problem is solved in latest H2 version. So H2 goes from version 1.3.168 to version 1.3.171. The issue concerns H2's Mysql MODE. The charset and encoding is mis-interpreted and fails.
Merge pull request #1074 from iammichiel/h2-upgrading

Upgrading H2 to latest version.