Call build_requester_credentials before yielding request if block_given?

Author: tenoriocesar

lib/ebay/api.rb

@@ -137,8 +137,8 @@ def commit(request_class, params, service_key = nil)
       end
 
       request = request_class.new(params)
-      yield request if block_given?
       build_requester_credentials(request)
+      yield request if block_given?
       invoke(request, format)
     end