#25-GPGPU-2 : Heat eqn : Fixes issue #71 (kdamping, not kambient)

As in the original Issue #71, the exercise text : 
```
The diffusion constant and damping will be sent in the parameters 
kdiffuse and kambient respectively.
```

didnt accurately reflect that one needs to add : 
```
uniform float kdiffuse, kdamping;
```

Fixed in the attached.
Martin
:-)