Change individual placement failure to warning (#1463)
Change individual placement failure to warning (#1463)

We are currently logging at error level for individual placement
failures which could be retried and could still succeed. This makes the
maximum log level for a per-placement-attempt failure a warning, and
reduces runner 503s to info level (since they are expected if the system
is under any kind of load)
fnproject/fn,fnproject/fn,fnproject/fn