- use validated creationdate_epoch delivered by search command

lib/SLUB/LZA/TA/Archivematica/Elasticsearch.pm

@@ -97,9 +97,9 @@ sub prepare_query ($opt) {
             }
         }
     }
-    if (exists $opt->{creationdate}) {
+    if (exists $opt->{creationdate_epoch}) {
         push @should, {
-            "created" => $opt->{creationdate}
+            "created" => $opt->{creationdate_epoch}
         };
     }
     if (exists $opt->{modificationdate}) {