Support `translate.google.com`

[liangkarl]

Hi @ryanker,

Thanks for this great browser extension for translation, I have a great experience with it. However, could you support translate.google.com instead of forcing to use translate.google.cn in the translation? It would help me a lot as it seems like translate.google.cn has some problems ouside of China. For the translate.google.cn, I've never seen it works, but I'm not sure whether or not it's related to the internet environments for different countries. Thanks.