Fix bugs for FGU remote_annoucement

Handle exception when category is missing

lib/remote_announcement.rb

@@ -3,7 +3,7 @@ require 'open-uri'
 require 'json'
 require 'date'
 
-@db = Mongo::Connection.new("localhost", 27017).db("fgu_orbit")
+@db = Mongo::Connection.new("localhost", 27017).db("test_site")
 @coll_bulletin = @db["bulletins"]
 @coll_cat =  @db["bulletin_categories"]
 
@@ -23,6 +23,7 @@ def get_remote_bulletins_json(url)
         lang = b[1]=='zh-tw' ? "zh_tw".to_sym : "en".to_sym
 
         next if b[2]==""
+        next if @categories["#{b[7]}"].nil?
 
         bulletin = {  _type: "Bulletin",
                     postdate: Time.parse(b[8]),