configure: Make the stack usage warning more strict
configure: Make the stack usage warning more strict

All the dev and release warning at the previous level have been fixed,
so tighten the warning a bit.

Signed-off-by: Rafael Ávila de Espíndola <1975039f9046bf513b77c0c5639a0efc25f00e7f@scylladb.com>
Message-Id: <20200413212241.365022-1-1975039f9046bf513b77c0c5639a0efc25f00e7f@scylladb.com>

scylladb/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla