tutorial: more general exception printout on startup
tutorial: more general exception printout on startup

When the start of the application fails (e.g., failed to parse command-
line options), print any exception we might have, and don't assume it
must be an std::runtime_error.

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>
Message-Id: <1466599342-18187-1-git-send-email-625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>

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