Handle HTTP specific errors then other errors when downloading rustc
Handle HTTP specific errors then other errors when downloading rustc

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