Revert to the default translations strings

Hello, I have a little problem: on the Theme Panel, I wanted to test the Translations options. I loaded another language to test. Then, when I wanted to go back to English, I had to load the English (default) one. But I have the feeling the performance of my website is affected since I have done this. I read that these translation strings are loaded form your server. Does that mean that now the English strings are located on your server rather than mine? This would be a problem: my server is in China and with the Great Firewall, any call / request outside of China slows down the website. Please let me know if I am correct in my analysis and if so, how to revert to the original settings . Many thanks

Ok, Thanks a lot for your reply on evato. I close here.