[컨텐츠][Common] 불필요 어노테이션 제거

app/src/main/java/kr/co/zumo/app/lifeplus/bean/api/ContentsItemBean.java

@@ -59,7 +59,6 @@ public class ContentsItemBean extends LifeplusContentsBean {
   @SerializedName("itemRecuList") // 이미지 아래 1. 2... 내용
   private List<ContentsDescriptionBean> descriptionList;
 
-  @SerializedName("waterMark")
   private String copyright;
 
   public String getListItemNo() {