reduce tag sub post limit

app/models/tag_subscription.rb

@@ -43,8 +43,9 @@ class TagSubscription < ActiveRecord::Base
   end
 
   def process
+    divisor = [tag_query_array.size / 2, 1].max
     post_ids = tag_query_array.inject([]) do |all, tag|
-      all += Post.tag_match(tag).limit(Danbooru.config.tag_subscription_post_limit / 3).select("posts.id").order("posts.id DESC").map(&:id)
+      all += Post.tag_match(tag).limit(Danbooru.config.tag_subscription_post_limit / divisor).select("posts.id").order("posts.id DESC").map(&:id)
     end
     self.post_ids = post_ids.sort.reverse.slice(0, Danbooru.config.tag_subscription_post_limit).join(",")
   end