enable building the game engine without bullet for scons & cmake

source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp

@@ -38,7 +38,6 @@
 #include "RAS_MeshObject.h"
 #include "KX_Scene.h"
 #include "SYS_System.h"
-#include "BulletSoftBody/btSoftBody.h"
 
 #include "PHY_Pro.h" //todo cleanup
 #include "KX_ClientObjectInfo.h"
@@ -56,6 +55,7 @@ extern "C"{
 }
 
 #ifdef USE_BULLET
+#include "BulletSoftBody/btSoftBody.h"
 
 #include "CcdPhysicsEnvironment.h"
 #include "CcdPhysicsController.h"
@@ -561,4 +561,4 @@ bool KX_ReInstanceBulletShapeFromMesh(KX_GameObject *gameobj, KX_GameObject *fro
 	spc->ReplaceControllerShape(bm);
 	return true;
 }
-#endif
+#endif // USE_BULLET