Unhelpful message abbrevation for E0277

[Xion]

A minor error message snafu:

error[E0277]: the trait bound `std::io::Error: std::convert::From<hyper::Error>` is not satisfied
   (code sample elided for brevity)
    = help: the following implementations were found:
              <std::io::Error as std::convert::From<std::ffi::NulError>>
              <std::io::Error as std::convert::From<std::io::IntoInnerError<W>>>
              <std::io::Error as std::convert::From<std::io::ErrorKind>>
              <std::io::Error as std::convert::From<slog::ser::Error>>
            and 1 others
    = note: required by `std::convert::From::from`
    = note: this error originates in a macro outside of the current crate

Notice the and 1 others line. It doesn't abbreviate anything; the compiler could've inserted the one missing impl and take the same amount of screen space.

[brson]

Just detect the case where there are 5 choices and print them all.