Update default RSS feeds

feeds.kodi.tv is/was handled by Google Feedburner, a service that is now largely obsolete and it is unclear how long it will still be available. Switch over to our normal webpage. Since it is fronted by Cloudflare, the traffic should not be a problem.

In the course of our website revamp, the addons feeds became unavailable. Remove them since they would be largely clutter anyway.

Also, lengthen the default update interval (there aren't so many updates anyway).

Author: yol

userdata/RssFeeds.xml

@@ -3,8 +3,6 @@
   <!-- RSS feeds. To have multiple feeds, just add a feed to the set. You can also have multiple sets. 	!-->
   <!-- To use different sets in your skin, each must be called from skin with a unique id.             	!-->
   <set id="1">
-    <feed updateinterval="30">http://feeds.kodi.tv/xbmc</feed>
-    <feed updateinterval="30">http://feeds.kodi.tv/latest_xbmc_addons</feed>
-    <feed updateinterval="30">http://feeds.kodi.tv/updated_xbmc_addons</feed>
+    <feed updateinterval="1440">https://kodi.tv/feed</feed>
   </set>
 </rssfeeds>