Due to db_change_column, _get_column_info has to call db_list_columns…

… requesting the details. - fixes #2109

sources/database/DbTable.class.php

@@ -202,7 +202,7 @@ protected function _alter_table($table_name, $statement)
 	 */
 	protected function _get_column_info($table_name, $column_name)
 	{
-		$columns = $this->db_list_columns($table_name, false);
+		$columns = $this->db_list_columns($table_name, true);
 
 		foreach ($columns as $column)
 		{