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'

<?xml version="1.0" encoding="ISO-8859-1" ?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:xhtml="http://www.w3.org/1999/xhtml">
  <xsd:element name="Python">
    <xsd:complexType>
      <xsd:annotation>
        <xsd:documentation>Formatted text according to parts of XHTML 1.1</xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
        <xsd:any namespace="http://www.w3.org/1999/xhtml" processContents="lax"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>