Fix method visiblity in emoji filter class

lib/banzai/filter/emoji_filter.rb

@@ -38,6 +38,11 @@ module Banzai
         end
       end
 
+      # Build a regexp that matches all valid :emoji: names.
+      def self.emoji_pattern
+        @emoji_pattern ||= /:(#{Gitlab::Emoji.emojis_names.map { |name| Regexp.escape(name) }.join('|')}):/
+      end
+
       private
 
       def emoji_url(name)
@@ -59,11 +64,6 @@ module Banzai
         ActionController::Base.helpers.url_to_image(image)
       end
 
-      # Build a regexp that matches all valid :emoji: names.
-      def self.emoji_pattern
-        @emoji_pattern ||= /:(#{Gitlab::Emoji.emojis_names.map { |name| Regexp.escape(name) }.join('|')}):/
-      end
-
       def emoji_pattern
         self.class.emoji_pattern
       end