Don't try and use a empty config path for startup scripts

Fix #9205

scripting/kicad_pyshell/__init__.py

@@ -39,6 +39,7 @@ class KiCadPyShell(KiCadEditorNotebookFrame):
         KiCadEditorNotebookFrame.__init__(self, parent)
 
     def _setup_startup(self):
+        if self.config_dir != "":
             """Initialise the startup script."""
             # Create filename for startup script.
             self.startup_file = os.path.join(self.config_dir,
@@ -65,6 +66,9 @@ class KiCadPyShell(KiCadEditorNotebookFrame):
                     default_startup.close()
                 except:
                     pass
+        else:
+            self.startup_file = ""
+            self.execStartupScript = False
 
     def _setup(self):
         """