Easy spacing fixes, trailing stuff

Remove useless trailing \
Remove trailing spaces
Add missing empty lines

autopep8 -ir -j2 --select=E301,E302,E502,W291,W293,W391 .

Diff quickly checked.

weboob/applications/qboobmsg/messages_manager.py

@@ -29,6 +29,7 @@ from weboob.tools.misc import to_unicode
 
 from .ui.messages_manager_ui import Ui_MessagesManager
 
+
 class MessagesManager(QWidget):
     def __init__(self, weboob, parent=None):
         QWidget.__init__(self, parent)