Fix doc

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/trunk@2499 b32b6428-25c9-4566-ad07-03861ab6144f

devices/notifications/pushbullet/xaal.pushbullet.ini

 [config]
 addr = xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
-key = xxxxxxxx
+keys = xxxxxxxx,yyyyyyy