sandbox: fixing bounded error for invalid access outside array
sandbox: fixing bounded error for invalid access outside array

JayKickliter/liquid-dsp,wangning223/liquid-dsp,jgaeddert/liquid-dsp,wangning223/liquid-dsp,JayKickliter/liquid-dsp,JayKickliter/liquid-dsp,jgaeddert/liquid-dsp,wangning223/liquid-dsp,wangning223/liquid-dsp,jgaeddert/liquid-dsp,jgaeddert/liquid-dsp,JayKickliter/liquid-dsp,JayKickliter/liquid-dsp,jgaeddert/liquid-dsp,wangning223/liquid-dsp