WebForms: Redundant message about missing block content on unpublished language version

Description

Steps to reproduce

1. Enable multiple languages in a site (e.g., English & Swedish [Svenska]).
2. In Swedish, create and publish a block (svBlock).
3. In English, create a page (enPage).
4. Drag and drop the svBlock onto the XhtmlString property on the enPage
5. Publish the enPage.
6. Open the enPage in View mode.

Expected: Block content is blank as its enBlock is not created and published.
Actual: Shows text No content found for this content fragment using content link '<block ID>' or content guid '...'