Adding logic to check if the user did some change on the config.site file, if this is the case we need to replace the config.site with the config.site.t and this will trigger all the configure scripts on the SDK since the configured target depends of build_start and this from config.site ( the change on the timestamp of config.site will trigger this). Adding this logic we will be checking for changes on config.site instead of just replace the file(change timestamp), avoiding a long wait during the compiling stage if it is not needed (avoiding to run the configure scripts)