wxGUI/vselect: fix BoxSizer widget Add method proportion param arg ty…

…pe (#2984)

BoxSizer widget Add method proportion param arg type must be integer
type. Fix is for Python 3.10 and wxPython 4.2.0 version.

gui/wxpython/gui_core/vselect.py

@@ -135,7 +135,7 @@ def CreateDialog(self, createButton=True):
             createMap = Button(
                 self._dialog, wx.ID_ANY, _("Create a new map"))
             createMap.Bind(wx.EVT_BUTTON, self.OnExportMap)
-            self._dialog.AddWidget(createMap, proportion=0.1)
+            self._dialog.AddWidget(createMap, proportion=0)
         self.slist = VectorSelectList(self._dialog)
         self.slist.Bind(wx.EVT_LIST_KEY_DOWN, self.OnDelete)
         self.slist.Bind(wx.EVT_LIST_ITEM_RIGHT_CLICK, self.OnDeleteRow)