Avoid dictionary initialization during import in PouDialog

Because initialization happened before i18n setup, then it causes later
problems during creating new POU on non-English locales (Russian for example).

Traceback (most recent call last):
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 2332, in OnAddPouMenu
dialog = PouDialog(self, pou_type, type_readonly)
File "/home/developer/WorkData/PLC/beremiz/beremiz/dialogs/PouDialog.py", line 101, in __init__
self.RefreshLanguage()
File "/home/developer/WorkData/PLC/beremiz/beremiz/dialogs/PouDialog.py", line 154, in RefreshLanguage
if language != "SFC" or PouDialog.POU_TYPES_DICT[self.PouType.GetStringSelection()] != "function":
KeyError: u'\u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430'

# 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"

# 4eb36c6be12e46c4a29c07bb1f68c553
#: ../../manual/edit.rst:2
msgid "Write your own POUs"
msgstr ""