fix clearing project name on opening project properties page.

The problem exists only on Windows with wxPython-3.0.

This happens because callback for EVT_KILL_FOCUS for a first text
control (project name) is called just after creating page with project
properties. It happens before initializing text controls from PLCController.

<?xml version="1.0" encoding="UTF-8"?>
<BaseParams Name="wxglade_hmi" IEC_Channel="0"/>