Translate Pro Sites Problem

I try to translate Pro Site by

1. go to pro-sitespro-sites-fileslanguagespsts-default.po on my desktop

2. i use Poedit and translate some wording and save as psts-th.mo (refer my wp-config.php define(‘WPLANG’, ‘th’:wink:; )

3. i upload to wp-content/plugins/pro-sites/pro-sites-files/languages/psts-th.mo

4. go to dashboard…..language not change?

Please suggest me, what i wrong?