[tldoc] Two small patches for messages.pot

[Siep Kroonenberg]

On Wed, Mar 10, 2021 at 11:04:47AM +0900, Norbert Preining wrote:
> Hi Vladimir,
> 
> thanks for the suggestions, but the pot file is automatically generated
> from the actual strings, so we need to update in the sources.
> 
> I have done that now, as well as updated all the .po and the
> messages.pot file.

The current GUI installer and tlshell have been modified too.

-- 
Siep Kroonenberg