wxGUI: Map Composer: fixed bug - don't select anything when list of images is empty

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@49340 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_modules/psmap_dialogs.py

@@ -5864,7 +5864,7 @@ class ImageDialog(PsmapDialog):
         if self.imageDict['epsfile']:
             file = os.path.basename(self.imageDict['epsfile'])
             self.imagePanel.image['list'].SetStringSelection(file)
-        else:
+        elif imageList:
             self.imagePanel.image['list'].SetSelection(0)
         self.OnImageSelectionChanged(None)