utils: managed_vector: Make copy assignment exception-safe
utils: managed_vector: Make copy assignment exception-safe

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