Proxy support

[librespeed-i2p]

I tried to set up librespeed in i2p, but encountered inaccurate results. While the download speed is measured quite accurately, the upload speed is unrealistically high. The thing is that when using a proxy (a necessary condition for configuring the service in i2p or tor), confirmation of data delivery during upload speed test occurs not when the data has actually been received by the server and the client has received a response from the server, but when the data has been received by the proxy server. If librespeed relied on the server and information about how much data has actually been received by the server when measuring upload speed, this would increase the accuracy of upload speed measurements when using a proxy. This is important for setting up librespeed in tor and i2p and in general when when configuring a librespeed instance with proxy.

[sstidl]

is there any question you have? any suggestion?