Don't load admin strings on the frontend
|Reported by:||nacin||Owned by:|
We should take the same approach as we did for multisite strings, and only load admin strings in the admin.
This should be handled in load_default_textdomain(). Additionally, includes/admin.php should load the admin mo file if it is not already loaded, in the case of the frontend calling on the admin bootstrap (which we, for example, do in admin-ajax).
This came out of #19832.