StartPublish not restored to original value after scheduling

Description

Even if a delayed publishing job has been executed, the StartPublish date still isn't restored to its original value. This is because the Save method is being called twice.

Steps to reproduce:

1. Create a page.
2. Give it a published date in the past.
3. Publish the page.
4. Change to the page you just created and schedule that change to be published in the near future.
5. Once that date has passed, run the Publish Delayed Content Versions job.

Expected:
The “Published” date should be restored to its original value from when it was previously published.

Actual:
The published page keeps the scheduled date as the “Published” date.