Removed line with no effect from constructor (aio-libs#430)

Author: carlopires

aiohttp_session/__init__.py

@@ -21,7 +21,6 @@ def __init__(self, identity, *, data, new, max_age=None):
         self._changed = False
         self._mapping = {}
         self._identity = identity if data != {} else None
-        self._new = new
         self._new = new if data != {} else True
         self._max_age = max_age
         created = data.get('created', None) if data else None