#193 Edit symbol crash when no symbol selected

[Anat]

Edit and all operations on symbol crash when no symbol selected

How to reproduce:

1. press the libraries.
2. choose to edit a library with 6 symbols or less.
3. stand on the empty space under all the others symbols.
4. right click and choose: edit symbol / delete symbols / symbol properties / duplicate symbol / copy to / export symbol to XML.
5. crash

[Anat]

The above is in version 2.80.08 build #631