Description

When Undo/Redo was added, this comparison was accidentally removed. The resulting conditional would always return true, causing sources to be deleted unintentionally.

Motivation and Context

Fixes #4546

How Has This Been Tested?

Click "No" when deleting multiple sources

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.