fix developer-mode parameter application on SMP
fix developer-mode parameter application on SMP

I am almost sure we want to apply it once on each shard, and not multiple
times on a single shard.

Message-Id: <65f25e9577eef5f1a4a9d7233f88dec2c7e2efb6@scylladb.com>

avikivity/scylla,scylladb/scylla,kjniemi/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,raphaelsc/scylla,kjniemi/scylla,raphaelsc/scylla,duarten/scylla,avikivity/scylla,scylladb/scylla,duarten/scylla,raphaelsc/scylla,kjniemi/scylla,scylladb/scylla