Additional fix for rewrite ForceVariableDialog commit (9076249f)

fix following backtrace:

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk3/wx/_core.py", line 16765, in <lambda>
lambda event: event.callable(*event.args, **event.kw) )
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/DebugVariablePanel/DebugVariableViewer.py", line 232, in HandleButton
button.ProcessCallback()
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/DebugVariablePanel/GraphButton.py", line 156, in ProcessCallback
self.Callback()
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/DebugVariablePanel/DebugVariableViewer.py", line 350, in OnForceButton
self.ForceValue(self.ItemsDict.values()[0])
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/DebugVariablePanel/DebugVariableViewer.py", line 428, in ForceValue
dialog.GetValue())
File "/home/developer/WorkData/PLC/beremiz/beremiz/dialogs/ForceVariableDialog.py", line 232, in GetValue
return GetTypeValue[self.IEC_Type](wx.TextEntryDialog.GetValue(self))
TypeError: unbound method GetValue() must be called with TextEntryDialog instance as first argument (got ForceVariableDialog instance instead)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# See COPYING.Runtime file for copyrights details.
#

from __future__ import absolute_import
from ctypes import CDLL, RTLD_GLOBAL, pointer, c_int, POINTER, c_char, create_string_buffer


def TryPreloadXenomai():
    """
    Xenomai 3 (at least for version <= 3.0.6) do not handle properly dlclose
    of shared objects whose dlopen did trigger xenomai_init.
    As a workaround, this pre-loads xenomai libraries that need to be
    initialized and call xenomai_init once for all.

    Xenomai auto init of libs MUST be disabled (see --auto-init-solib in xeno-config)
    """
    try:
        for name in ["cobalt", "modechk", "copperplate", "alchemy"]:
            globals()[name] = CDLL("lib"+name+".so", mode=RTLD_GLOBAL)
        cobalt.xenomai_init(pointer(c_int(0)), pointer((POINTER(c_char)*2)(create_string_buffer("prog_name"), None)))
    except Exception:
        pass