wxGUI: fix vdigit toolbar (selection arrow button) with wxPython 3

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@62606 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_core/toolbars.py

@@ -263,8 +263,8 @@ class BaseToolbar(wx.ToolBar):
             bitmap = wx.Bitmap(name = arrowPath)
         else:
             bitmap = wx.ArtProvider.GetBitmap(id = wx.ART_MISSING_IMAGE, client = wx.ART_TOOLBAR)
-        button =  wx.BitmapButton(parent = self, id = wx.ID_ANY, size = ((-1, self.GetSize()[1])),
-                                  bitmap = bitmap, style = wx.NO_BORDER)
+        button =  wx.BitmapButton(parent=self, id=wx.ID_ANY, size=((-1, self.GetToolSize()[1])),
+                                  bitmap=bitmap, style=wx.NO_BORDER)
         button.SetToolTipString(tooltip)
 
         return button