Fix gate-trove-functional-dsvm-{datastore}

Reasons:
 - not all datastores have full int-test coverage;
 - int tests should be lauched with specific --group
   parameters for each datastore except mysql.

Changes:
 - fixing command that lauches int-tests for datastores;

Change-Id: If786545e9986145c0ded2a33b1f7acd0efc26bee
Merge "Fix gate-trove-functional-dsvm-{datastore}"