Fix a crash when a member is an empty object.
Fix a crash when a member is an empty object.

LiuDeng/JsonToJava,hgl888/JsonToJava,jonfhancock/JsonToJava,linyh1993/JsonToJava,linyh1993/JsonToJava,linyh1993/JsonToJava,LiuDeng/JsonToJava,hgl888/JsonToJava,hgl888/JsonToJava,LiuDeng/JsonToJava,jonfhancock/JsonToJava