Undo?

I was about to modify a value after login in my admin and accessing the front of the page where I used the free plugin to create a column. My hand slipped after I hovered over the column and revealed the wireframe, and in one second the mouse had grabbed a corner of the wireframe and dragged it a few inches.

Since then, the column structure had changed and I cannot undo the action.

When I hover over the toolbar, there is a message that reads: “This layout has unpublished changes.”

(Screenshot ► https://gyazo.com/8b77de83a777c562cf4075b964d14bd6)

How do I UNDO this, or CANCEL the changes?

Thank you!

The page I need help with: [log in to see the link]