Fix the oauth 1.4 issuex

Author: chussenot

lib/omniauth/strategies/linkedin.rb

@@ -63,10 +63,6 @@ def raw_info
         @raw_info ||= access_token.get("/v1/people/~:(#{option_fields.join(',')})?format=json").parsed
       end
 
-      def callback_url
-        options[:callback_url] || super
-      end
-
       private
 
       def option_fields