chore: Translate pressbooks-multi-institution.pot in fr

73% of minimum 25% translated source file: 'pressbooks-multi-institution.pot'
on 'fr'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

languages/pressbooks-multi-institution-fr_FR.po

@@ -277,7 +277,7 @@ msgstr ""
 
 #: resources/views/dashboard/institutional.blade.php:17
 msgid "%s has %s books and %s users. "
-msgstr ""
+msgstr "%s a %s livres et %s utilisateurs."
 
 #: resources/views/dashboard/institutional.blade.php:24
 msgid "Administer"