Description:
------------
pg_query_params seems to be converting boolean "false" parameters to an empty string before sending the query to Postgres, resulting in the following error:

ERROR: invalid input syntax for type boolean: ""

Reproduce code:
---------------
Create a table:

CREATE TABLE test (id serial8, flag boolean);

Execute this php script:

<?php
$conn = pg_connect('host=localhost dbname=test user=user password=pass');
pg_query_params($conn, 'INSERT INTO test (flag) VALUES ($1)', array(false));
?>



Expected result:
----------------
A new row should be inserted with the correct boolean field value.

Actual result:
--------------
ERROR: invalid input syntax for type boolean: ""