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'?>
<BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema" URI_location="LOCAL://">
  <TargetType/>
</BeremizRoot>