Problem description:
Removing an empty header or footer from the document creates a warning about deleting text. This warning is confusing as no text will be deleted.

Steps to reproduce:
1. Click near the top of the page so the 'Header (Default style)' button appears
2. Click it to add the header, but do not add any text into the header
3. Click it again to open the menu, and select 'delete header'

Current behavior:
A warning dialog appears, with the text "Removing headers or footers deletes the contents.
Do you want to delete this text?"

Expected behavior:
If the header/footer being deleted is empty, do not display a warning about it.
              
Operating System: All
Version: 4.1.4.2 release