[-] Removed unneeded include.

code/glTFAsset.h

@@ -54,7 +54,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <vector>
 #include <algorithm>
 #include <stdexcept>
-#include <cstdlib>
 
 #define RAPIDJSON_HAS_STDSTRING 1
 #include <rapidjson/rapidjson.h>