Moved configuring linear problem in MultiObjective
Moved configuring linear problem in MultiObjective

This had to be moved to add_objective so that it is set when
constructing MultiObjective by summing.

eusoubrasileiro/fatiando_seismic,mtb-za/fatiando,fatiando/fatiando,cmeessen/fatiando,rafaelmds/fatiando,drandykass/fatiando,victortxa/fatiando,rafaelmds/fatiando,eusoubrasileiro/fatiando,cmeessen/fatiando,eusoubrasileiro/fatiando,victortxa/fatiando,santis19/fatiando,santis19/fatiando,fatiando/fatiando,eusoubrasileiro/fatiando_seismic,mtb-za/fatiando,drandykass/fatiando,eusoubrasileiro/fatiando