Illegal flag in wx/ui_panel.py. FIX INCLUDED

[jmoraleda]

Recent versions of wxWidgets are more strict about not allowing positioning flags that have no effect so one gets the error:

  File "/usr/lib/python3/dist-packages/traits/has_traits.py", line 2019, in edit_traits
    return view.ui(
  File "/usr/lib/python3/dist-packages/traitsui/view.py", line 446, in ui
    ui.ui(parent, kind)
  File "/usr/lib/python3/dist-packages/traitsui/ui.py", line 244, in ui
    self.rebuild(self, parent)
  File "/usr/lib/python3/dist-packages/traitsui/wx/toolkit.py", line 115, in ui_subpanel
    ui_panel.ui_subpanel(ui, parent)
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 101, in ui_subpanel
    ui_panel_for(ui, parent, False)
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 115, in ui_panel_for
    ui.control = control = Panel(ui, parent, buttons).control
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 202, in __init__
    sw = panel(ui, cpanel)
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 306, in panel
    sg_sizer, resizable, contents = fill_panel_for_group(
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 467, in fill_panel_for_group
    fp = FillPanel(panel, group, ui, suppress_label, is_dock_window,
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 613, in __init__
    self.add_items(content, panel, self.sizer)
  File "/usr/lib/python3/dist-packages/traitsui/wx/ui_panel.py", line 1041, in add_items
    item_sizer.Add(control, growable,
wx._core.wxAssertionError: C++ assertion "!(flags & wxALIGN_CENTRE_VERTICAL)" failed at /home/jorge/vc/Phoenix/ext/wxWidgets/src/common/sizer.cpp(2109) in DoInsert(): Vertical alignment flags are ignored in vertical sizers

FIX

To fix it, it suffices to remove | wx.ALIGN_CENTER_VERTICAL from line 1042 of wx/ui_panel.ui