When an inline was left on a rendered DocumentEngine document, don't include an email context patch

Summary:
Ref T13513. If you leave an inline on line 20 of a Jupyter document, we currently render context around *raw* line 20, which is inevitably some unrelated piece of JSON.

Instead, drop this context. (Ideal behavior would be to render context around Jupyter block 20, but that's a whole lot of work.)

Test Plan:

• On Jupyter changes and normal source changes, made and submitted inline comments, then viewed text and HTML mail.
• Saw no context on Jupyter comments (instead of bad context), and unchanged behavior (useful context) on normal source changes.

Maniphest Tasks: T13513

Differential Revision: https://secure.phabricator.com/D21242