Remove Unneeded `PermissionKeyCategory::getByID()`

`PermissionKey::add()` gets a new `PermissionKeyCategory` by id but does
not use it.

- Remove call to `PermissionKeyCategory::getByID()`
Merge pull request #1583 from mkly/remove_unneeded_get_category_permission_key_add

Remove Unneeded `PermissionKeyCategory::getByID()`