Autocomplete doesn't work in ST/IL editors

[Andrey Skvortsov]

1. Open first_steps example
2. Open CounterST or CounterIL example
3. Click on text program
4. Press 'Ctrl-space'

Traceback (most recent call last):
  File "/home/developer/WorkData/PLC/beremiz/beremiz/editors/TextViewer.py", line 891, in OnKeyDown
    self.Editor.AutoCompShow(len(words[-1]), " ".join(kw))
  File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk3/wx/stc.py", line 3036, in AutoCompShow
    return _stc.StyledTextCtrl_AutoCompShow(*args, **kwargs)
PyAssertionError: C++ assertion "litem >= 0 && (size_t)litem < GetItemCount()" failed at ../src/generic/listctrl.cpp(3422) in SetItemState(): invalid list ctrl item index in SetItem