Don't send the referrer to Twitter servers when no proxy

When no proxy is activated. You need to not send a referrer to Twitter servers because if you do you get a 403.

https://matrix.to/#/!PclMnsCNeemgMBWtvC:snopyta.org/$mAuPdptsTIUKxrUbvTMlpNXgUVZzcEvUS9MWiaj7NLk?via=nolog.chat&via=matrix.org&via=tchncs.de

We use the referrer policy with "same-origin" in order to not send the referrer for website outside of the main domain of where nitter is hosted.