Fix for #23577. Check if db tables for config data exists before fetch data.

Author: ivanko-dev

app/code/Magento/Store/App/Config/Source/RuntimeConfigSource.php

@@ -83,12 +83,17 @@ private function getConnection()
      */
     private function getEntities($table, $keyField)
     {
-        $entities = $this->getConnection()->fetchAll(
-            $this->getConnection()->select()->from($this->resourceConnection->getTableName($table))
-        );
         $data = [];
-        foreach ($entities as $entity) {
-            $data[$entity[$keyField]] = $entity;
+        $tableName = $this->resourceConnection->getTableName($table);
+        // Check if db table exists before fetch data
+        if($this->resourceConnection->getConnection()->isTableExists($tableName)) {
+            $entities = $this->getConnection()->fetchAll(
+                $this->getConnection()->select()->from($tableName)
+            );
+
+            foreach ($entities as $entity) {
+                $data[$entity[$keyField]] = $entity;
+            }
         }
 
         return $data;