btKartRaycast.cpp: fix usage with new bullet

We need to apply patch when we compiling STK with new version of bullet
libraries.

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Reference: https://github.com/ignatenkobrain/stk-code/commit/49f52006c8ccec631e7e169b3fac94f8862f1ea1