replaced hardcoded english string

public/language/en_GB/topic.json

@@ -6,6 +6,8 @@
 	"no_topics_found": "No topics found!",
 	"no_posts_found": "No posts found!",
 
+	"post_is_deleted": "This post is deleted!",
+
 	"profile": "Profile",
 	"posted_by": "Posted by %1",
 	"chat": "Chat",

src/topics/posts.js

@@ -70,7 +70,7 @@ module.exports = function(Topics) {
 					postData[i].display_move_tools = results.privileges[i].move;
 
 					if(postData[i].deleted && !results.privileges[i].view_deleted) {
-						postData[i].content = 'This post is deleted!';
+						postData[i].content = '[[topic:post_is_deleted]]';
 					}
 				}