Merge pull request #2642 from artzavod/patch

Query with subqueries exception fix.

Author: yajra

src/QueryDataTable.php

@@ -767,7 +767,9 @@ protected function showDebugger(array $output)
     {
         $query_log = $this->connection->getQueryLog();
         array_walk_recursive($query_log, function (&$item) {
-            $item = utf8_encode($item);
+            if (is_string($item)) {
+                $item = utf8_encode($item);
+            }
         });
 
         $output['queries'] = $query_log;