HyperTreeList: TR_ELLIPSIZE_LONG_ITEMS problem when main column > 0

[Jorilx]

Operating system: Devuan 3 (similar to Debian 10) wxPython version & source: 4.1.0 from https://extras.wxpython.org/wxPython4/extras/linux/gtk3/debian-10 Python version & source: 2.7.16 from distro

If you create a HyperTreeList with TR_ELLIPSIZE_LONG_ITEMS and SetMainColumn(x) where x > 0, every label of that column gets truncated as just ...

I think this is due to https://github.com/wxWidgets/Phoenix/blob/af8cca5189ff1241fc7d2112e70131ac3788a0db/wx/lib/agw/hypertreelist.py#L3201

it should be

maxsize = col_w - (text_x - x_colstart) - _MARGIN