seastar-addr2line: support address-only object_address
seastar-addr2line: support address-only object_address

Currently object_address_re requires a prefix for each addres.
That isn't available with the oneline backtrace format.

Also, use re.IGNORECASE to support also upper-case
hexidecimal addresses.

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@scylladb.com>

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