Fix crash when a model defined a className property.
Fix crash when a model defined a className property.

jianwoo/JSONModel,izrie/JSONModel,ramoslin02/JSONModel,CareEvolution/JSONModel,TerryAsh/JSONModel,billinghamj/JSONModel,cczallen/JSONModel,iwakevin/JSONModel,jianwoo/JSONModel,yarec/JSONModel,dalu93/JSONModel,chenkaige/JSONModel,yunzhongyoulong/JSONModel,LiuShulong/JSONModel,SampleLiao/JSONModel,youprofit/JSONModel,liwangbest/JSONModel,AlJaMa/JSONModel,johnmyqin/JSONModel,db42/JSONModel,jsonmodel/jsonmodel,zwcshy/JSONModel,zwcshy/JSONModel,SummerHF/JSONModel,scottdinggo/JSONModel,SatanWoo/JSONModel,kerrmarin/jsonmodel,hfossli/JSONModel,MellongLau/JSONModel,dbachrach/JSONModel,huiping192/JSONModel,ernestopino/JSONModel,billinghamj/JSONModel,NiuMengFei/JSONModel,SanjoDeundiak/JSONModel,SongYuJie1989/JSONModel,icanzilb/JSONModel,xunan623/JSONModel,xxclouddd/JSONModel,redlinesolutions/JSONModel,ThirakornP/JSONModel,MaWenxing/JSONModel,zhou18520786640/JSONModel,liuyujing/JSONModel