The second typed listed number isn't listed automatically if previously was deleted

[SoftVision-CarmenFat]

[Affected versions]:

• Firefox Notes 1.8.0 rc6
• Firefox 56 and up

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• Have a Firefox profile with the latest "Firefox Notes" add-on version (1.8.0 rc6) installed.

[Steps to reproduce]:

1. Open the browser with the profiles from prerequisites.
2. Click the "Numbered List" button and write a string.
3. Press "Enter" key and delete the "2." listed automatically.
4. Type "2." and press space.
5. Observe what happens next.

[Expected result]:

• The "2." string is automatically listed in the numbered list.

[Actual result]:

• The "2. " string is not listed.

[Notes]:

• The string is automatically numbered listed only if typing "1." instead of "2."
• Bug reference: The second typed listed number isn't listed automatically if previously was deleted mozilla/notes#290
• Attached a screen recording of the issue: