removed unused language strings from previous sidebar

public/language/en_GB/category.json

@@ -1,9 +1,6 @@
 {
 	"new_topic_button": "New Topic",
 	"no_topics": "<strong>There are no topics in this category.</strong><br />Why don't you try posting one?",
-	"sidebar.recent_replies": "Recent Replies",
-	"sidebar.active_participants": "Active Participants",
-	"sidebar.moderators": "Moderators",
 	"posts": "posts",
 	"views": "views",
 	"posted": "posted",