file type manager cannot change width

[Dig Ge]

Open FileTypeManager tab, 2 columns on the right, but the width cannot be changed.

By set "set_resizable" to True, it can drag, and still cannot show full text (renderer limited)

def __add_columns(self):
    column = gtk.TreeViewColumn(_('File Type'))
+ column.set_resizable(True)

    renderer = gtk.CellRendererPixbuf()
    column.pack_start(renderer, False)