API testcase minor fix
API testcase minor fix

Avoid refcount expect string because refcount may change in some situations
like shuffle torture tests.

nivertech/duktape,tassmjau/duktape,tassmjau/duktape,zeropool/duktape,harold-b/duktape,svaarala/duktape,tassmjau/duktape,harold-b/duktape,markand/duktape,zeropool/duktape,jmptrader/duktape,zeropool/duktape,markand/duktape,jmptrader/duktape,harold-b/duktape,tassmjau/duktape,markand/duktape,markand/duktape,markand/duktape,chenyaqiuqiu/duktape,harold-b/duktape,harold-b/duktape,chenyaqiuqiu/duktape,chenyaqiuqiu/duktape,jmptrader/duktape,nivertech/duktape,zeropool/duktape,svaarala/duktape,jmptrader/duktape,jmptrader/duktape,zeropool/duktape,svaarala/duktape,zeropool/duktape,harold-b/duktape,harold-b/duktape,svaarala/duktape,tassmjau/duktape,tassmjau/duktape,chenyaqiuqiu/duktape,chenyaqiuqiu/duktape,svaarala/duktape,tassmjau/duktape,nivertech/duktape,harold-b/duktape,markand/duktape,chenyaqiuqiu/duktape,svaarala/duktape,jmptrader/duktape,svaarala/duktape,zeropool/duktape,jmptrader/duktape,markand/duktape,nivertech/duktape,nivertech/duktape,markand/duktape,markand/duktape,svaarala/duktape,tassmjau/duktape,chenyaqiuqiu/duktape,harold-b/duktape,tassmjau/duktape,markand/duktape,harold-b/duktape,jmptrader/duktape,nivertech/duktape,nivertech/duktape,chenyaqiuqiu/duktape,nivertech/duktape,zeropool/duktape,jmptrader/duktape,zeropool/duktape,nivertech/duktape,jmptrader/duktape,svaarala/duktape,tassmjau/duktape,chenyaqiuqiu/duktape,zeropool/duktape,chenyaqiuqiu/duktape,nivertech/duktape