wxGUI/iclass: fix https://trac.osgeo.org/grass/changeset/54399

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@54400 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/iclass/g.gui.iclass.py

@@ -52,6 +52,7 @@ from core.giface    import StandaloneGrassInterface
 from iclass.frame   import IClassMapFrame
 
 def main():
+    group_name = map_name = None
     if options['group']:
         group_name = grass.find_file(name = options['group'], element = 'group')['name']
         if not group_name: