make a worksheet and save it on sagenb.org: it doesn't have a .sws extension anymore!

[williamstein]

I upgraded sagenb.org to sagenb-0.5 and am having the above problem. ARgh.

Component: notebook

Issue created by migration from https://trac.sagemath.org/ticket/7896

[williamstein]

comment:1

Evidently, I was just panicked. This is invalid.