Bug#1011697: wxpython4.0: FTBFS with SIP 6.6

[Sebastiaan Couwenberg]

Upstream has changes to fix building with SIP 6.6:

 https://github.com/wxWidgets/Phoenix/pull/2179
But this is blocked because there is no SIP 6.6.2 release yet with many 
fixes for the new ply based parser.