test update_nowait - added support in MariaDB-10.3

test update_nowait - added support in MariaDB-10.3

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MariaDB supported NOWAIT in 10.3.

ref: https://mariadb.com/kb/en/wait-and-nowait/

This pull request is:

- [X] very trivial test change
- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [ ] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #7009
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7009
Pull-request-sha: 4fa750e3d34638be7e9583d849216f6d90ca88fc

Change-Id: I4ee8cf2cf84daf7af3300e6f80671375232fcf02