[Bug] IndexError after right click on 'GRASS Locations in...' in the Data tab

[wenzeslaus]

Describe the bug
"list index out of range" error appears in the Console tab in GUI after right click on the database directory ("grassdata") node (root) in the Data tab.

To Reproduce
Steps to reproduce the behavior:

1. Start GRASS GIS with GUI
2. Click on Data
3. Right click on the root item "GRASS Locations in ..."
4. Click on Console
5. See the traceback

Expected behavior
In the future, there should be some actual functionality on the right click there, but for fixing this ticket, only not producing any traceback, i.e., really no action, is the desired behavior.

Full traceback

Traceback (most recent call last):
  File "/home/vpetras/dev/grass/grass/dist.x86_64-pc-linux-
gnu/gui/wxpython/gui_core/treeview.py", line 72, in <lambda>

self._emitSignal(evt.GetItem(), self.contextMenu))
  File "/home/vpetras/dev/grass/grass/dist.x86_64-pc-linux-
gnu/gui/wxpython/gui_core/treeview.py", line 175, in
_emitSignal

signal.emit(node=node, **kwargs)
  File "/home/vpetras/dev/grass/grass/dist.x86_64-pc-linux-
gnu/etc/python/grass/pydispatch/signal.py", line 229, in
emit

dispatcher.send(signal=self, *args, **kwargs)
  File "/home/vpetras/dev/grass/grass/dist.x86_64-pc-linux-
gnu/etc/python/grass/pydispatch/dispatcher.py", line 344, in
send

response = robustapply.robustApply(
  File "/home/vpetras/dev/grass/grass/dist.x86_64-pc-linux-
gnu/etc/python/grass/pydispatch/robustapply.py", line 60, in
robustApply

return receiver(*arguments, **named)
  File "/home/vpetras/dev/grass/grass/dist.x86_64-pc-linux-
gnu/gui/wxpython/datacatalog/tree.py", line 478, in
OnRightClick

if self.selected_layer[0]:
IndexError
:
list index out of range

System description (please complete the following information):

• Operating System: Linux, Ubuntu 20.04
• GRASS GIS version: 7.9
• wxPython: 4.0.7