compressor: allow an empty map of options
compressor: allow an empty map of options

Signed-off-by: Paweł Dziepak <e29bb3265626c60caf76d587cabdfcd8b379ef80@cloudius-systems.com>

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