Tweaks on max group items in recommendation job 2, a=chris

diff --git a/src/library/media_jobs/RecommendationJob.php b/src/library/media_jobs/RecommendationJob.php
index 72ba48cb7..87d8778d0 100644
--- a/src/library/media_jobs/RecommendationJob.php
+++ b/src/library/media_jobs/RecommendationJob.php
@@ -354,7 +354,7 @@ class RecommendationJob extends MediaJob
         $num_items = 0;
         if ($results) {
             $row = $db->fetchArray($results);
-            $num_items = max($row['NUM_ITEMS'], self::MAX_GROUP_ITEMS) ?? 0;
+            $num_items = min($row['NUM_ITEMS'], self::MAX_GROUP_ITEMS) ?? 0;
         }
         $num_batches = ceil($num_items/self::MAX_BATCH_SIZE);
         L\crawlLog("Number of group items will consider: " . $num_items);