db/schema_tables: Fix calculate_schema_digest()
db/schema_tables: Fix calculate_schema_digest()

map_reduce() can run the reducer out-of-order which breaks the MD5 hash.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Fixes #357. [tgrabiec]

respu/scylla,acbellini/scylla,raphaelsc/scylla,gwicke/scylla,shaunstanislaus/scylla,scylladb/scylla,tempbottle/scylla,duarten/scylla,avikivity/scylla,scylladb/scylla,guiquanz/scylla,tempbottle/scylla,avikivity/scylla,asias/scylla,rentongzhang/scylla,phonkee/scylla,eklitzke/scylla,justintung/scylla,glommer/scylla,asias/scylla,avikivity/scylla,wildinto/scylla,victorbriz/scylla,aruanruan/scylla,eklitzke/scylla,shaunstanislaus/scylla,guiquanz/scylla,kjniemi/scylla,gwicke/scylla,duarten/scylla,kangkot/scylla,acbellini/scylla,stamhe/scylla,raphaelsc/scylla,senseb/scylla,linearregression/scylla,senseb/scylla,bowlofstew/scylla,rentongzhang/scylla,capturePointer/scylla,senseb/scylla,rluta/scylla,kjniemi/scylla,scylladb/scylla,glommer/scylla,guiquanz/scylla,victorbriz/scylla,asias/scylla,raphaelsc/scylla,wildinto/scylla,respu/scylla,capturePointer/scylla,dwdm/scylla,dwdm/scylla,wildinto/scylla,rluta/scylla,aruanruan/scylla,linearregression/scylla,stamhe/scylla,capturePointer/scylla,justintung/scylla,scylladb/scylla,glommer/scylla,rentongzhang/scylla,duarten/scylla,phonkee/scylla,justintung/scylla,respu/scylla,shaunstanislaus/scylla,aruanruan/scylla,phonkee/scylla,kangkot/scylla,gwicke/scylla,tempbottle/scylla,eklitzke/scylla,bowlofstew/scylla,victorbriz/scylla,linearregression/scylla,bowlofstew/scylla,stamhe/scylla,acbellini/scylla,kjniemi/scylla,dwdm/scylla,rluta/scylla,kangkot/scylla