Don't unnecessarily clone entire `opts::Opt` structure.
Don't unnecessarily clone entire `opts::Opt` structure.

`opts::Opt` is a pretty big structure, so cloning everything is
excessive when we only need a few items.

canaltinova/servo,ConnorGBrewster/servo,CJ8664/servo,peterjoel/servo,notriddle/servo,nnethercote/servo,thiagopnts/servo,mbrubeck/servo,thiagopnts/servo,anthgur/servo,splav/servo,KiChjang/servo,mattnenterprise/servo,emilio/servo,dati91/servo,splav/servo,pyfisch/servo,thiagopnts/servo,SimonSapin/servo,upsuper/servo,peterjoel/servo,notriddle/servo,anthgur/servo,anthgur/servo,jimberlage/servo,KiChjang/servo,larsbergstrom/servo,DominoTree/servo,fiji-flo/servo,larsbergstrom/servo,mbrubeck/servo,thiagopnts/servo,pyfisch/servo,upsuper/servo,fiji-flo/servo,mbrubeck/servo,dati91/servo,mattnenterprise/servo,avadacatavra/servo,splav/servo,peterjoel/servo,saneyuki/servo,paulrouget/servo,pyfisch/servo,saneyuki/servo,cbrewster/servo,ConnorGBrewster/servo,KiChjang/servo,sadmansk/servo,KiChjang/servo,mattnenterprise/servo,fiji-flo/servo,cbrewster/servo,thiagopnts/servo,eddyb/servo,emilio/servo,pyfisch/servo,upsuper/servo,eddyb/servo,dsandeephegde/servo,SimonSapin/servo,paulrouget/servo,anthgur/servo,jimberlage/servo,upsuper/servo,KiChjang/servo,peterjoel/servo,saneyuki/servo,avadacatavra/servo,paulrouget/servo,DominoTree/servo,sadmansk/servo,cbrewster/servo,jimberlage/servo,jimberlage/servo,paulrouget/servo,szeged/servo,peterjoel/servo,splav/servo,saneyuki/servo,notriddle/servo,cbrewster/servo,KiChjang/servo,fiji-flo/servo,ConnorGBrewster/servo,DominoTree/servo,larsbergstrom/servo,nnethercote/servo,dsandeephegde/servo,pyfisch/servo,fiji-flo/servo,larsbergstrom/servo,ConnorGBrewster/servo,CJ8664/servo,notriddle/servo,DominoTree/servo,pyfisch/servo,emilio/servo,nnethercote/servo,rnestler/servo,sadmansk/servo,cbrewster/servo,mbrubeck/servo,CJ8664/servo,thiagopnts/servo,KiChjang/servo,szeged/servo,thiagopnts/servo,fiji-flo/servo,upsuper/servo,ConnorGBrewster/servo,fiji-flo/servo,notriddle/servo,DominoTree/servo,DominoTree/servo,ConnorGBrewster/servo,emilio/servo,ConnorGBrewster/servo,canaltinova/servo,nnethercote/servo,mbrubeck/servo,DominoTree/servo,upsuper/servo,jimberlage/servo,SimonSapin/servo,larsbergstrom/servo,emilio/servo,avadacatavra/servo,jimberlage/servo,peterjoel/servo,saneyuki/servo,ConnorGBrewster/servo,anthgur/servo,rnestler/servo,upsuper/servo,splav/servo,dsandeephegde/servo,szeged/servo,CJ8664/servo,avadacatavra/servo,sadmansk/servo,emilio/servo,cbrewster/servo,rnestler/servo,anthgur/servo,jimberlage/servo,DominoTree/servo,mbrubeck/servo,saneyuki/servo,notriddle/servo,nnethercote/servo,avadacatavra/servo,paulrouget/servo,emilio/servo,nnethercote/servo,larsbergstrom/servo,CJ8664/servo,paulrouget/servo,canaltinova/servo,paulrouget/servo,larsbergstrom/servo,mattnenterprise/servo,splav/servo,rnestler/servo,eddyb/servo,dati91/servo,SimonSapin/servo,mattnenterprise/servo,pyfisch/servo,splav/servo,nnethercote/servo,nnethercote/servo,szeged/servo,sadmansk/servo,szeged/servo,mattnenterprise/servo,rnestler/servo,canaltinova/servo,pyfisch/servo,jimberlage/servo,paulrouget/servo,szeged/servo,dsandeephegde/servo,CJ8664/servo,saneyuki/servo,paulrouget/servo,rnestler/servo,dsandeephegde/servo,splav/servo,dati91/servo,emilio/servo,thiagopnts/servo,nnethercote/servo,larsbergstrom/servo,dsandeephegde/servo,anthgur/servo,peterjoel/servo,pyfisch/servo,saneyuki/servo,szeged/servo,eddyb/servo,szeged/servo,paulrouget/servo,SimonSapin/servo,fiji-flo/servo,eddyb/servo,DominoTree/servo,CJ8664/servo,canaltinova/servo,nnethercote/servo,notriddle/servo,notriddle/servo,pyfisch/servo,mbrubeck/servo,splav/servo,peterjoel/servo,eddyb/servo,dsandeephegde/servo,szeged/servo,peterjoel/servo,eddyb/servo,anthgur/servo,saneyuki/servo,sadmansk/servo,larsbergstrom/servo,SimonSapin/servo,upsuper/servo,KiChjang/servo,mattnenterprise/servo,SimonSapin/servo,avadacatavra/servo,sadmansk/servo,peterjoel/servo,dati91/servo,jimberlage/servo,CJ8664/servo,mattnenterprise/servo,notriddle/servo,SimonSapin/servo,avadacatavra/servo,saneyuki/servo,canaltinova/servo,notriddle/servo,dsandeephegde/servo,szeged/servo,cbrewster/servo,rnestler/servo,emilio/servo,emilio/servo,dati91/servo,rnestler/servo,avadacatavra/servo,dati91/servo,dati91/servo,canaltinova/servo,eddyb/servo,canaltinova/servo,sadmansk/servo,splav/servo,mbrubeck/servo,cbrewster/servo,KiChjang/servo,DominoTree/servo,larsbergstrom/servo,KiChjang/servo