Facebook tag set focus issue.

Steps:

1. Create new e.g article.
2. Add facebook tag.
3. Insert value into Post URL field.
4. Save.
5. Edit the tag.
6. In the Post URL field select everything using keyboard shortcut cmd+a (not the mouse).
7. Insert new value.
8. Save.

Actual result: Console error `Uncaught TypeError: Cannot read property 'setFocused' of null` (attached). Saving is blocked.

Remarks: Does not occur if selection in step 6 is made with mouse double-click.