[Collab] Tollbar Cancel button is always shown as pressed after it is clicked RMB

To reproduce:
1. Create a new project
2. Push it to collab
3. Click Cancel button using RMB while pushing changes
4. Click LMB on this button
5. Notice that button is still working

Expected vs Actual: button should not become greyed out/always shown as pressed after it is clicked RMB

Reproduced: 2017.1.3f1, 2017.2.1p3, 2017.3.2f1, 2017.4.1f1, 2018.1.0b13, 2018.2.0a9
Not reproducible: 5.6.5p2, 2017.1.0f1