This reverts commit b56ba02335.
After commit 8fa35d6ddf (messaging_service: Get rid of timeout and retry
logic for streaming verb), streaming verb in rpc does not check if a
node is in gossip memebership since all the retry logic is removed.
Remove the extra wait before removing the joining node from gossip
membership.
Message-Id: <a416a735bb8aad533bbee190e3324e6b16799415.1504063598.git.asias@scylladb.com>