dependencies: upgrade express-session 1.16.1 -> 1.17.0
dependencies: upgrade express-session 1.16.1 -> 1.17.0

This upgrade should be backward compatible.
Changelog:
- https://github.com/expressjs/session/blob/master/HISTORY.md

1.17.0 / 2019-10-10
    deps: cookie@0.4.0
        Add SameSite=None support
    deps: safe-buffer@5.2.0

1.16.2 / 2019-06-12
    Fix restoring cookie.originalMaxAge when store returns Date
    deps: parseurl@~1.3.3

joequant/etherpad-lite,joequant/etherpad-lite,aptivate/etherpad-lite,ether/etherpad-lite,joequant/etherpad-lite,joequant/etherpad-lite,aptivate/etherpad-lite,ether/etherpad-lite,aptivate/etherpad-lite,storytouch/etherpad-lite,ether/etherpad-lite,aptivate/etherpad-lite,storytouch/etherpad-lite,storytouch/etherpad-lite