We did the clean up in idl/gossip_digest.idl.hh, but the patch to clean
up gms/application_state.hh was never merged.
To maintain compatibility with previous version of scylla, we can not
change application_state.hh, instead change idl to be sync with
application_state.hh.
Message-Id: <3a78b159d5cb60bc65b354d323d163ce8528b36d.1458557948.git.asias@scylladb.com>