Issue #1891728 by gielfeldt: Fixed DatabaseSchema_mysql()::getComment() does...

Issue #1891728 by gielfeldt: Fixed DatabaseSchema_mysql()::getComment() does not work for targets other than 'default'.

core/lib/Drupal/Core/Database/Driver/mysql/Schema.php

@@ -49,7 +49,7 @@ protected function getPrefixInfo($table = 'default', $add_prefix = TRUE) {
     }
     else {
       $db_info = Database::getConnectionInfo();
-      $info['database'] = $db_info['default']['database'];
+      $info['database'] = $db_info[$this->connection->getTarget()]['database'];
       $info['table'] = $table;
     }
     return $info;