pep8 blank lines fixes

flake8 --select W391,E302,E301,E304

autopep8 can't fix W391 even though it claims it can.
Fixed using a simple custom script.

weboob/deprecated/browser/parsers/csvparser.py

@@ -29,6 +29,7 @@ class Csv(object):
     rows contains the raw rows
     drows contains the rows with cells indexed by header title
     """
+
     def __init__(self):
         self.header = None
         self.rows = []