[Sample Issue]: Edit Labyrinth: Delete node functionality doesn't work

[ykorvel]

Steps to reproduce:

• Login to OL with "user" / "user" credentials at http://samplelink.com/login
• Find labyrinth "1" at the list in "Open Labyrinths" section
• Go to Edit Labyrinth page, direct link http://samplelink.com
• Go to Nodes section at the page, direct link http://samplelink.com
• Select any node, and click at "delete" link

Actual result:

• Nothing happened, page doesn’t refreshed. See screenshot attached.

Expected result:

• User should see confirmation JS pop-up at first (like on screenshot attached). Then if "Yes" selected, node should be removed from the page.

If "No" selected on pop-up, then nothing should happened - user should see the same content on the page.