modified so that its is internationalized

resource/locales/en_US/translation.json

@@ -327,7 +327,8 @@
       "New page name": "New page name",
       "Fail to get subordinated pages": "Fail to get subordinated pages",
       "Current page name": "Current page name",
-      "Duplicate with child": "Duplicate with child"
+      "Duplicate with child": "Duplicate with child",
+      "Same page already exists": "Same page already exists"
     }
   },
   "modal_putback": {

resource/locales/ja_JP/translation.json

@@ -329,7 +329,8 @@
       "New page name": "複製後のページ名",
       "Fail to get subordinated pages": "配下ページの取得に失敗しました",
       "Current page name": "現在のページ名",
-      "Duplicate with child": "配下のページも一緒に複製する"
+      "Duplicate with child": "配下のページも一緒に複製する",
+      "Same page already exists": "同じページがすでに存在します"
     }
   },
   "modal_putback": {

resource/locales/zh_CN/translation.json

@@ -302,7 +302,8 @@
       "New page name": "New page name",
       "Fail to get subordinated pages": "Fail to get subordinated pages",
 			"Current page name": "Current page name",
-			"Duplicate with child": "Duplicate with child"
+      "Duplicate with child": "Duplicate with child",
+      "Same page already exists": "Same page already exists"
 		}
 	},
 	"modal_putback": {

src/client/js/components/PageDuplicateModal.jsx

@@ -135,7 +135,7 @@ const PageDuplicateModal = (props) => {
               {isDuplicateRecursively && subordinatedPaths.map((duplicatedNewPath) => {
                   // ToDo: The "true" statement below will be modified by task GW3503
                   if (true) {
-                    return <li className="duplicate-exist" key={duplicatedNewPath}>{duplicatedNewPath}: Same page already exists</li>;
+                    return <li className="duplicate-exist" key={duplicatedNewPath}>{duplicatedNewPath}: { t('modal_duplicate.label.Same page already exists') }</li>;
                   }
                   return <li key={duplicatedNewPath}>{duplicatedNewPath}</li>;
                 })