Sessions: Can no more switch back to (empty) default session

Before QC 4.5 it was possible to do the following:

• start QC [no existing sessions]
• use the session manager to create and switch to a new session
• open some projects and files inside this session
• open the session manager again to switch back to the empty default session

Current result:

• switching to the default session seems to happen (according to the title bar and welcome screen)
• default session contains now the project(s) opened inside the session created above, same applies for the opened docs