PHP Extension - Inconsistent final modifier for Google\Protobuf\Timestamp

[FabioBatSilva]

In PHP C extension implementation of Google\Protobuf\Timestamp is marked as final but not in the native PHP implementation.

This creates inconsistency between the two:

PHP Implementation :

protobuf/php/src/Google/Protobuf/Timestamp.php

Line 82 in e3ac4c9

class Timestamp extends \Google\Protobuf\Internal\TimestampBase

C Implementation

protobuf/php/ext/google/protobuf/wkt.inc

Line 1616 in e3ac4c9

google_protobuf_Timestamp_ce->ce_flags |= ZEND_ACC_FINAL;