FIX: update oEmbed URL for simplecast onebox (#13956)

lib/onebox/engine/simplecast_onebox.rb

@@ -23,13 +23,7 @@ module Onebox
       private
 
       def get_oembed_url
-        if id = url.scan(/([a-zA-Z0-9]*)\Z/).flatten.first
-          oembed_url = "https://simplecast.com/s/#{id}"
-        else
-          oembed_url = url
-        end
-
-        "https://simplecast.com/oembed?url=#{oembed_url}"
+        "https://api.simplecast.com/oembed?url=#{url}"
       end
     end
   end