XWIKI-21577: Ratings improperly remove ratings with 0 even if zero stored is allowed

* remove unused import

xwiki-platform-core/xwiki-platform-ratings/xwiki-platform-ratings-api/src/test/java/org/xwiki/ratings/internal/SolrRatingsManagerTest.java

@@ -28,7 +28,6 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;