Fixes https://forum.voxelands.com/viewtopic.php?id=893 (btw I'd advise adding an explanatory comment when closing a bug report as "NOT A BUG" -- it is a bug in this case).
Before this fix, trying to build voxelands out of source (e.g.
mkdir build && cd build && cmake .. && make) would fail to include
src in the include paths. I removed the
CMAKE_BUILD_TYPE include as it seems to be a typo (it would be
RelWithDebInfo, not sure why that would be relevant as include path).