re-activate ignored test

Author: thjaeckle

thingsearch/service/src/test/java/org/eclipse/ditto/thingsearch/service/starter/actors/AggregateThingsMetricsActorTest.java

@@ -48,7 +48,6 @@
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
@@ -66,7 +65,6 @@
 import de.flapdoodle.reverse.TransitionWalker;
 
 @RunWith(Parameterized.class)
-@Ignore("TODO temporarily ignored for release")
 public class AggregateThingsMetricsActorTest {
 
     @ClassRule