XFCE clear worspaces shortcuts

Collision is present in hotkeys with default xfce installation and PhpStorm software.
There are useful shortcuts in PhpStorm to navigate in the code: Ctrl + Alt + Left / Right, but xfce is using them for switching workspaces.

To make keycodes work in PhpStorm you should disable them from capturing in your OS.
It could be done without restarting XFCE.

Go to Settings->Window Manager->Keyboard. Scroll down to Left Workspace and click on a "Clear" button. Same for a Right Workspace.