[BUGFIX] set site field on record documents in same way as on pages

Fixes: #3459
Ports: #4413

Author: dkd-kaehm

Classes/Domain/Search/ApacheSolrDocument/Builder.php

@@ -124,8 +124,10 @@ public function fromRecord(array $itemRecord, string $type, int $rootPageUid, st
         $document->setField('type', $type);
         $document->setField('appKey', 'EXT:solr');
 
-        // site, siteHash
-        $document->setField('site', $site->getDomain());
+        $document->setField('site', $site->getSiteIdentifier());
+        if ($this->extensionConfiguration->getSiteHashStrategy() === 0) {
+            $document->setField('site', $site->getDomain());
+        }
         $document->setField('siteHash', $site->getSiteHash());
 
         // uid, pid