Fix missing translation

[fenestron]

Missing translation.

In addition, I would like to say that for the translation to be complete I also needed to add these lines to the ui.php file:

    'Type your folder name here' => 'Type your folder name here',
    'Name' => 'Name',
    'Showing' => 'Showing',
    'to' => 'to',
    'of' => 'of',
    'Files' => 'Files',
    'Folder Name' => 'Folder Name',
    'Folders' => 'Folders',
    'Rename Folder' => 'Rename Folder',
    'This folder is empty' => 'This folder is empty',
    'You can upload a new file or create a new folder' => 'You can upload a new file or create a new folder',