fixed concurrent modification in TbSubscriptionsInfo

application/src/main/java/org/thingsboard/server/service/subscription/TbSubscriptionsInfo.java

@@ -20,6 +20,7 @@ import lombok.EqualsAndHashCode;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
+import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -48,7 +49,7 @@ public class TbSubscriptionsInfo {
     }
 
     protected TbSubscriptionsInfo copy(int seqNumber) {
-        return new TbSubscriptionsInfo(notifications, alarms, tsAllKeys, tsKeys, attrAllKeys, attrKeys, seqNumber);
+        return new TbSubscriptionsInfo(notifications, alarms, tsAllKeys, tsKeys != null ? new HashSet<>(tsKeys) : null, attrAllKeys, attrKeys != null ? new HashSet<>(attrKeys) : null, seqNumber);
     }
 
 }