TASK: Skip "error" message during index build

When / and /sites are to be indexed, it is rather unsurprising to not
find a fulltext root. Thus this changes skips these messages:

    NodeIndexer: No fulltext root found for node / (...)
    NodeIndexer: No fulltext root found for node /sites (0...)

for the root and sites node.

Author: kdambekalns

Classes/Driver/AbstractIndexerDriver.php

@@ -48,7 +48,9 @@ protected function findClosestFulltextRoot(NodeInterface $node)
             $closestFulltextNode = $closestFulltextNode->getParent();
             if ($closestFulltextNode === null) {
                 // root of hierarchy, no fulltext root found anymore, abort silently...
-                $this->logger->log(sprintf('NodeIndexer: No fulltext root found for node %s (%s)', $node->getPath(), $node->getIdentifier()), LOG_WARNING, null, 'ElasticSearch (CR)');
+                if ($node->getPath() !== '/' && $node->getPath() !== '/sites') {
+                    $this->logger->log(sprintf('NodeIndexer: No fulltext root found for node %s (%s)', $node->getPath(), $node->getIdentifier()), LOG_WARNING, null, 'ElasticSearch (CR)');
+                }
 
                 return null;
             }