Fix rare data corruption issue with TB128

In rare cases we can't quite identify, scheduled drafts are getting corrupted when they are saved by Send Later. This appears to be a race condition related to the fact that we compact the Drafts folder immediately after saving a draft. As a workaround, which seems to work, for the time being we are delaying the compact for a second after saving the draft.

Note: Downloading and installing send_later_beta.xpi will subscribe you to future beta releases. We love beta-testers! The advantage is that if there's a bug that affects your workflow you'll help find it and get it fixed quickly. The disadvantage is that bugs are a bit more likely in beta releases. You can unsubscribe from beta releases at any time by downloading and installing send_later.xpi or installing from addons.thunderbird.net.