ProjectExplorer: Regression: Missing 'Close Project "xyz"' in context menu of project node

Steps to reproduce:

• have at least two projects opened inside QC
• right click onto one of the project nodes

Expected result:

• there's a menu item stating 'Close Project "xyz"' with 'xyz' the name of the project

Current result:

• this menu item is missing in latest master (it's still present in 3.2)

Note: this menu item exists if there's only one project opened in QC