reqwest::Error now less informative

[Smotrov]

With updated version to_string() trait method of reqwest::Error is now not the informative when in case when there is a connection error. It is always only error sending request now.
Before it was something like error sending request: operation timed out,
error sending request: connection closed before message completed, error sending request: connection error: Connection reset by peer (os error 104) etc.
Now it is much harder to investigate what is causing the issues. Would be grate to bring back previous descriptions.

[seanmonstar]

I know, it's not ideal. But it's also expected by a lot of other people: hyperium/hyper#2732

The idea is that you would use some sort of error reporter (such as the eventually stable std::error::Report) that will print each error message, following it's source chain. If each error printed the chain itself, you'd have a lot of duplication.