Remove unused use_nightly_rust function.
Remove unused use_nightly_rust function.

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