POST_OAUTH_LOGIN_SESSION_KEY is never used

[maligree]

The connect handler does this:

pc = request.form.get('next', allow_view)
session[config_value('POST_OAUTH_CONNECT_SESSION_KEY')] = pc

The login handler does this:

post_login = request.form.get('next', get_post_login_redirect())
session['post_oauth_login_url'] = post_login

Ignoring any custom key set in the config. Minor, I know, but someone could eventually bump into this or something.