Session token is shown in new launcher

The bug

The old launcher was changed to not log the session ID to prevent the user from accidentially sharing it when publishing their log (MCL-3715).
Newer Minecraft versions do not log the session ID anymore, however older ones still do and the new launcher is not censoring them (neither in the GUI nor the launcher_log.txt and the game log file):

(Session ID is token: ###)

How to reproduce

1. Start Minecraft 1.8
2. Search in the log for "Session ID is token"