The translations are longer than they need to be, the translations below are shorter and can be read more fluently:
MUI_TEXT_INSTALLING_SUBTITLE "Veuillez patienter pendant l'installation de $(^NameDA)."
MUI_UNTEXT_UNINSTALLING_SUBTITLE "Veuillez patienter pendant la désinstallation de $(^NameDA)."
French.nsh modified from NSIS 2.46