ZCU-DATA/Reduce ClarinItemServiceImpl approximate date log from WARN to DEBUG (#1284)

Changed 'Cannot update item dates metadata because the approximate date
is empty' from WARN to DEBUG level to reduce log noise.

Author: milanmajchrak

dspace-api/src/main/java/org/dspace/content/clarin/ClarinItemServiceImpl.java

@@ -220,7 +220,7 @@ public void updateItemDatesMetadata(Context context, Item item) throws SQLExcept
 
         String derivedDate = deriveDateIssuedFromApproximateDate(item);
         if (derivedDate == null) {
-            log.warn("Cannot update item dates metadata because the approximate date is empty.");
+            log.debug("Cannot update item dates metadata because the approximate date is empty.");
             return;
         }