fix bug that appears if datatype in the project tree is renamed to wrong name (keyword, existend type,...)

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk2/wx/_core.py", line 16765, in <lambda>
lambda event: event.callable(*event.args, **event.kw) )
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk2/wx/lib/expando.py", line 126, in _adjustCtrl
numLines = self.GetNumberOfLines()
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk2/wx/_core.py", line 16710, in __getattr__
raise PyDeadObjectError(self.attrStr % self._name)
PyDeadObjectError: The C++ part of the TreeTextCtrl object has been deleted, attribute access no longer allowed.

# SOME DESCRIPTIVE TITLE.
# Copyright (C) is 21st century inquisition
# This file is distributed under the same license as the Beremiz package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: Beremiz 1.1\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2012-09-08 01:21\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"Language: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

# 085a2a1c2a1043d7b09d75d0c657d2a3
#: ../../manual/debug.rst:2
msgid "Trace POUs instances variable"
msgstr ""