a bug with legendskin in API

I have a dynamic layer in my project. If I change the defaultvisibility by code, got error in legendskin in line 631. The reason is parentLayerId is null, but the condition check is (= -1) Here's the fix

at line 631, the original code is if (layerInfos[i].parentLayerId != -1)

change to if(!( (layerInfos[i].parentLayerId = -1 ) || isNaN(layerInfos[i].parentLayerId) ))

Best,

Xiaowen