Fix medusa segfaults
We run medusa
on boss against experiment nodes to look for authentication issues in VNC. The version we use, 2.2 from 2016, is the latest released version but has core-dump issues. @stoller has tried tracking these down and so have I. The latest upgrade on boss and ops (to FreeBSD 12.2) seems to have exacerbated the problem and put it back on my radar.