Bug report

Describe the bug

When an image is not selected in the project, the right click options in this area have an additional line separation that is not required.
Right click on the project when an image is selected gives you many options. When an image is not selected, then the options is less but the separation line still remains at the very top, looking slightly odd.

To Reproduce

Steps to reproduce the behavior:

1. Make sure an image is not open or selected in an open project
2. Right click on the project tab
3. Note the additional line at the top thats not required

Expected behavior

No line should appear when an image is not selected. The line should remain when an image is as there will be additional options that do not relate to the ones below.

Screenshots

Desktop (please complete the following information):

• OS: All
• QuPath Version: 0.6.0

Additional context

Add any other context about the problem here.