BUG #13744: Postgresql function auto add 's' character to the end of string

The following bug has been logged on the website:

Bug reference:      13744
Logged by:          Bang
Email address:      b.phamhuu@jacobs-university.de
PostgreSQL version: 9.2.13
Operating system:   Centos 7
Description:

I've a function in Postgresql database. However, every time I run the
function in postgresql, it auto add character 's' behind of the query so it
will be error when execute (for example: WHAT IN HERE: query SELECT uom_id
FROM ps_quantity where id = 11s ). My version is Postgresql 9.2.13. How can
I solve this?

 CREATE OR REPLACE FUNCTION select_field(
    selected_table text,
    selected_field text,
    field_type_sample anyelement,
    where_clause text DEFAULT ''::text)
  RETURNS anyelement AS
$BODY$ DECLARE
    -- Log
    ME  constant text := 'selected_field()';
    -- Local variables
        _qry          varchar := '';
        _result_value ALIAS FOR $0;
    where_clause1 varchar := 'asdasdsad';
    BEGIN
    RAISE NOTICE 'FUNCTION: SELECT_FIELD';
    -- BANGPH
    RAISE NOTICE 'BANGPH - CHANGE 11s to 11';

        _qry := 'SELECT uom_id FROM ps_quantity where id = 11';

    RAISE NOTICE 'WHERE = %s', where_clause1;

    RAISE NOTICE 'WHAT IN HERE: query %s', _qry;