http/routes: Remove request failure logging to stderr
http/routes: Remove request failure logging to stderr

There's no real need to log the request failure at Seastar level because
the information is propagated to callers. Remove the logging to clean up
annoying spam when Scylla boots up and a JMX proxy races with it's API
server startup.

Message-Id: <fadfc62cf06a79a5cf1012fd403655f0f15ee0a8@scylladb.com>

cloudius-systems/seastar,avikivity/seastar,avikivity/seastar,kjniemi/seastar,syuu1228/seastar,cloudius-systems/seastar,dreamsxin/seastar,dreamsxin/seastar,scylladb/seastar,scylladb/seastar,avikivity/seastar,dreamsxin/seastar,cloudius-systems/seastar,syuu1228/seastar,scylladb/seastar,kjniemi/seastar,syuu1228/seastar,kjniemi/seastar