remove deleted enable_nacl_nonsfi gn flag

build/GN_ARGS

@@ -16,7 +16,6 @@ enable_iterator_debugging=false
 enable_mdns=false
 enable_mse_mpeg2ts_stream_parser=true
 enable_nacl=false
-enable_nacl_nonsfi=false
 enable_platform_dolby_vision=true
 enable_platform_hevc=true
 enable_remoting=false