wxGUI: use default style for splash screen (extrastyle has been removed in 2.8.11)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@45640 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/wxgui.py

@@ -1484,7 +1484,6 @@ class GMApp(wx.App):
         introBmp       = introImage.ConvertToBitmap()
         if SC:
             splash = SC.AdvancedSplash(bitmap = introBmp, 
-                                       extrastyle = SC.AS_TIMEOUT | SC.AS_CENTER_ON_SCREEN,
                                        timeout = 2000, parent = None, id = wx.ID_ANY)
             splash.SetText(_('Starting GRASS GUI...'))
             splash.SetTextColour(wx.Colour(45, 52, 27))