[Bug] Save as STL for single component saves with wrong name if a componet tree has been saved as One File Per Body

[thomasa88]

1. Select a component with children and choose Save as STL.

2. Choose "One File Per Body"

3. Press OK. You don't have to actually save the files.

4. Select a component without children and choose Save as STL.

5. The dialog will now look like this. Notice the "Structure" being set to "One File Per Body".

6. Press OK.

7. Note the filename and save the file.

8. Expected: File will have the given name.
     Observed: File is named "<parent component><component>.stl"