Description:
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pg_insert in PHP 7.0.6 fails to insert timestamps, in PHP 5.6.21 it works.

Test script:
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PostgreSQL commands:

$ createdb test
$ createuser test

PHP commands:

$ php -a
Interactive shell

php > $res = pg_connect("host=localhost dbname=test user=test");
php > pg_query($res, "CREATE TABLE test (ts TIMESTAMP)");
php > pg_insert($res, 'test', ['ts' => '2016-01-01T15:00:00+0100']);
PHP Notice:  pg_insert(): Expects NULL or string for PostgreSQL timestamp field (ts) in php shell code on line 1

Notice: pg_insert(): Expects NULL or string for PostgreSQL timestamp field (ts) in php shell code on line 1

(PHP 5.6.21: last line succeeds with no output.)

Expected result:
----------------
No output

Actual result:
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PHP Notice