Add link to download all worksheets as a zip file for accounts=True

[TimDumol]

This is already present in the codebase introduced by Robert Bradshaw and revised by William Stein, but there is no link to the url for the file.

CC: @jasongrout @williamstein

Component: notebook

Author: Tim Dumol

Reviewer: Mitesh Patel

Merged: sagenb-0.7

Issue created by migration from https://trac.sagemath.org/ticket/7962

[TimDumol]

Simple 2 line patch removing the {% if not accounts %} tags.

[TimDumol]

comment:1

Attachment: trac_7962-link-worksheets-zip-file.patch.gz

[jasongrout]

comment:2

#7963 needs to be fixed, probably before this ticket is fixed.

[qed777]

Reviewer: Mitesh Patel