Merge branch 'release/v2.5.1'
* Fix: variable name $sub['id'] should be $sub_id in admin submissions view

This error caused a PHP Notice on the admin page that lists submissions.
It was introduced with 1e39788a2ea6e21b8a3d55674924bb1731653de1
Merge pull request #197 from NateWr/master

Fix: variable name $sub['id'] should be $sub_id in admin submissions view