#8 fix for new ODE 0.6

[Anonymous]

This is the first time I am doing a patch so please
forgive any errors. The patch fixes a call to
dAreConnectedExcluding which requires (via assertion)
that both bodies are not null. The current gansta
implementation somtimes passes bodies which are null
into this function (ie collision only geoms which have
null bodies). This fix only changes one line in the
PhysicsDriver_ODE in the gaworld_ode.cpp at
approximatly line 200. The ode assertion does not get
called once this line is updated and it seems like the
integrity of the collisions is kept although I stand
corrected under the project admin.

[Nobody/Anonymous]