net/storage_task.rs: Fix remove_item
net/storage_task.rs: Fix remove_item

Use `and_then` and remove `unwrap` instead of using a `map` as described in https://github.com/servo/servo/issues/5548#issuecomment-90254644.

thiagopnts/servo,dagnir/servo,saneyuki/servo,KiChjang/servo,avadacatavra/servo,codemac/servo,rentongzhang/servo,mbrubeck/servo,mdibaiee/servo,tschneidereit/servo,notriddle/servo,saneyuki/servo,mt2d2/servo,aweinstock314/servo,jgraham/servo,rentongzhang/servo,hyowon/servo,dsandeephegde/servo,upsuper/servo,dvberkel/servo,rnestler/servo,nnethercote/servo,walac/servo,jlegendary/servo,canaltinova/servo,zhangjunlei26/servo,boghison/servo,wartman4404/servo,KiChjang/servo,mdibaiee/servo,aidanhs/servo,KiChjang/servo,j3parker/servo,dhananjay92/servo,ryancanhelpyou/servo,dati91/servo,fiji-flo/servo,pyfisch/servo,caldwell/servo,runarberg/servo,wartman4404/servo,upsuper/servo,CJ8664/servo,sadmansk/servo,WriterOfAlicrow/servo,dsandeephegde/servo,rnestler/servo,s142857/servo,DominoTree/servo,splav/servo,upsuper/servo,eddyb/servo,huonw/servo,huonw/servo,ConnorGBrewster/servo,DominoTree/servo,dagnir/servo,zentner-kyle/servo,meh/servo,nerith/servo,jimberlage/servo,anthgur/servo,mbrubeck/servo,caldwell/servo,SimonSapin/servo,jlegendary/servo,akosel/servo,dhananjay92/servo,ConnorGBrewster/servo,runarberg/servo,bjwbell/servo,dhananjay92/servo,kindersung/servo,aweinstock314/servo,nrc/servo,meh/servo,zentner-kyle/servo,nick-thompson/servo,deokjinkim/servo,brendandahl/servo,hyowon/servo,dsandeephegde/servo,dhananjay92/servo,avadacatavra/servo,fiji-flo/servo,zhangjunlei26/servo,peterjoel/servo,tschneidereit/servo,steveklabnik/servo,GreenRecycleBin/servo,mdibaiee/servo,youprofit/servo,rnestler/servo,rnestler/servo,splav/servo,kindersung/servo,tafia/servo,dvberkel/servo,jgraham/servo,ryancanhelpyou/servo,meh/servo,emilio/servo,ConnorGBrewster/servo,larsbergstrom/servo,anthgur/servo,SimonSapin/servo,emilio/servo,mbrubeck/servo,walac/servo,GreenRecycleBin/servo,karlito40/servo,kindersung/servo,karlito40/servo,wpgallih/servo,tafia/servo,dagnir/servo,youprofit/servo,dagnir/servo,SimonSapin/servo,j3parker/servo,jlegendary/servo,pgonda/servo,pyecs/servo,DominoTree/servo,WriterOfAlicrow/servo,saratang/servo,zentner-kyle/servo,evilpie/servo,j3parker/servo,eddyb/servo,eddyb/servo,dvberkel/servo,codemac/servo,aweinstock314/servo,mt2d2/servo,canaltinova/servo,g-k/servo,jimberlage/servo,upsuper/servo,hyowon/servo,dati91/servo,mdibaiee/servo,samfoo/servo,brendandahl/servo,deokjinkim/servo,hyowon/servo,notriddle/servo,emilio/servo,GreenRecycleBin/servo,youprofit/servo,ConnorGBrewster/servo,codemac/servo,cbrewster/servo,emilio/servo,caldwell/servo,AnthonyBroadCrawford/servo,nnethercote/servo,runarberg/servo,A-deLuna/servo,rentongzhang/servo,CJ8664/servo,GreenRecycleBin/servo,mbrubeck/servo,tempbottle/servo,fiji-flo/servo,wpgallih/servo,upsuper/servo,larsbergstrom/servo,saneyuki/servo,rentongzhang/servo,huonw/servo,larsbergstrom/servo,walac/servo,tschneidereit/servo,sadmansk/servo,evilpie/servo,aweinstock314/servo,larsbergstrom/servo,SimonSapin/servo,s142857/servo,AnthonyBroadCrawford/servo,larsbergstrom/servo,wpgallih/servo,akosel/servo,j3parker/servo,bjwbell/servo,GreenRecycleBin/servo,tempbottle/servo,DominoTree/servo,zentner-kyle/servo,huonw/servo,pyecs/servo,caldwell/servo,walac/servo,boghison/servo,jimberlage/servo,s142857/servo,rixrix/servo,emilio/servo,vks/servo,j3parker/servo,AnthonyBroadCrawford/servo,fiji-flo/servo,vks/servo,aidanhs/servo,szeged/servo,kindersung/servo,peterjoel/servo,zhangjunlei26/servo,dsandeephegde/servo,KiChjang/servo,nrc/servo,jdramani/servo,steveklabnik/servo,eddyb/servo,wpgallih/servo,pyecs/servo,DominoTree/servo,thiagopnts/servo,nick-thompson/servo,cbrewster/servo,DominoTree/servo,tafia/servo,hyowon/servo,pgonda/servo,pyfisch/servo,aweinstock314/servo,bjwbell/servo,pyfisch/servo,dagnir/servo,ConnorGBrewster/servo,jgraham/servo,jdramani/servo,nnethercote/servo,g-k/servo,jlegendary/servo,GreenRecycleBin/servo,jlegendary/servo,wpgallih/servo,akosel/servo,rnestler/servo,rixrix/servo,GyrosOfWar/servo,jdramani/servo,upsuper/servo,KiChjang/servo,kindersung/servo,zhangjunlei26/servo,tempbottle/servo,mattnenterprise/servo,WriterOfAlicrow/servo,meh/servo,deokjinkim/servo,peterjoel/servo,szeged/servo,samfoo/servo,mattnenterprise/servo,anthgur/servo,dati91/servo,dati91/servo,wartman4404/servo,tschneidereit/servo,nrc/servo,s142857/servo,upsuper/servo,bjwbell/servo,meh/servo,akosel/servo,akosel/servo,aidanhs/servo,anthgur/servo,ryancanhelpyou/servo,s142857/servo,nerith/servo,thiagopnts/servo,wpgallih/servo,nnethercote/servo,splav/servo,bjwbell/servo,s142857/servo,A-deLuna/servo,jimberlage/servo,samfoo/servo,GreenRecycleBin/servo,emilio/servo,dagnir/servo,g-k/servo,eddyb/servo,rentongzhang/servo,avadacatavra/servo,cbrewster/servo,CJ8664/servo,tempbottle/servo,ConnorGBrewster/servo,boghison/servo,hyowon/servo,hyowon/servo,steveklabnik/servo,sadmansk/servo,mbrubeck/servo,pyfisch/servo,saratang/servo,deokjinkim/servo,peterjoel/servo,saratang/servo,paulrouget/servo,tschneidereit/servo,rixrix/servo,anthgur/servo,boghison/servo,g-k/servo,dvberkel/servo,RenaudParis/servo,WriterOfAlicrow/servo,codemac/servo,wpgallih/servo,canaltinova/servo,notriddle/servo,DominoTree/servo,samfoo/servo,pgonda/servo,zentner-kyle/servo,szeged/servo,peterjoel/servo,KiChjang/servo,peterjoel/servo,cbrewster/servo,brendandahl/servo,canaltinova/servo,saneyuki/servo,aidanhs/servo,GreenRecycleBin/servo,paulrouget/servo,mattnenterprise/servo,notriddle/servo,caldwell/servo,jlegendary/servo,evilpie/servo,youprofit/servo,evilpie/servo,nerith/servo,thiagopnts/servo,ryancanhelpyou/servo,saneyuki/servo,brendandahl/servo,eddyb/servo,tafia/servo,pyfisch/servo,j3parker/servo,mbrubeck/servo,SimonSapin/servo,saneyuki/servo,cbrewster/servo,splav/servo,nick-thompson/servo,GreenRecycleBin/servo,nnethercote/servo,mt2d2/servo,A-deLuna/servo,karlito40/servo,tafia/servo,jimberlage/servo,notriddle/servo,larsbergstrom/servo,CJ8664/servo,mbrubeck/servo,aweinstock314/servo,KiChjang/servo,dsandeephegde/servo,pyecs/servo,notriddle/servo,splav/servo,thiagopnts/servo,rixrix/servo,jgraham/servo,GyrosOfWar/servo,dvberkel/servo,dvberkel/servo,samfoo/servo,jdramani/servo,bjwbell/servo,DominoTree/servo,paulrouget/servo,rentongzhang/servo,cbrewster/servo,pyfisch/servo,deokjinkim/servo,caldwell/servo,rnestler/servo,rnestler/servo,steveklabnik/servo,peterjoel/servo,nick-thompson/servo,codemac/servo,nick-thompson/servo,runarberg/servo,steveklabnik/servo,anthgur/servo,KiChjang/servo,akosel/servo,larsbergstrom/servo,youprofit/servo,vks/servo,aweinstock314/servo,huonw/servo,mattnenterprise/servo,peterjoel/servo,rixrix/servo,sadmansk/servo,nrc/servo,mattnenterprise/servo,pgonda/servo,avadacatavra/servo,fiji-flo/servo,dati91/servo,thiagopnts/servo,paulrouget/servo,RenaudParis/servo,cbrewster/servo,nrc/servo,jimberlage/servo,dhananjay92/servo,zhangjunlei26/servo,codemac/servo,nerith/servo,pyfisch/servo,mattnenterprise/servo,nnethercote/servo,AnthonyBroadCrawford/servo,g-k/servo,jlegendary/servo,anthgur/servo,AnthonyBroadCrawford/servo,karlito40/servo,WriterOfAlicrow/servo,wartman4404/servo,nnethercote/servo,saratang/servo,notriddle/servo,karlito40/servo,steveklabnik/servo,avadacatavra/servo,pyfisch/servo,brendandahl/servo,nrc/servo,WriterOfAlicrow/servo,cbrewster/servo,jgraham/servo,s142857/servo,dsandeephegde/servo,mt2d2/servo,saneyuki/servo,runarberg/servo,zhangjunlei26/servo,dhananjay92/servo,brendandahl/servo,evilpie/servo,walac/servo,zhangjunlei26/servo,jgraham/servo,saneyuki/servo,wartman4404/servo,vks/servo,dhananjay92/servo,dagnir/servo,RenaudParis/servo,splav/servo,wpgallih/servo,splav/servo,avadacatavra/servo,mdibaiee/servo,GyrosOfWar/servo,jdramani/servo,nerith/servo,paulrouget/servo,mattnenterprise/servo,evilpie/servo,emilio/servo,thiagopnts/servo,runarberg/servo,jdramani/servo,WriterOfAlicrow/servo,rixrix/servo,deokjinkim/servo,nick-thompson/servo,g-k/servo,jimberlage/servo,jgraham/servo,CJ8664/servo,A-deLuna/servo,boghison/servo,dati91/servo,larsbergstrom/servo,canaltinova/servo,tempbottle/servo,paulrouget/servo,canaltinova/servo,ryancanhelpyou/servo,avadacatavra/servo,saneyuki/servo,tschneidereit/servo,peterjoel/servo,samfoo/servo,karlito40/servo,mdibaiee/servo,szeged/servo,larsbergstrom/servo,rnestler/servo,zentner-kyle/servo,thiagopnts/servo,ConnorGBrewster/servo,meh/servo,aidanhs/servo,anthgur/servo,mattnenterprise/servo,jdramani/servo,GyrosOfWar/servo,pyecs/servo,tempbottle/servo,youprofit/servo,SimonSapin/servo,aidanhs/servo,peterjoel/servo,AnthonyBroadCrawford/servo,GyrosOfWar/servo,splav/servo,wartman4404/servo,jimberlage/servo,sadmansk/servo,tempbottle/servo,SimonSapin/servo,szeged/servo,karlito40/servo,AnthonyBroadCrawford/servo,dsandeephegde/servo,ConnorGBrewster/servo,boghison/servo,szeged/servo,mt2d2/servo,pgonda/servo,samfoo/servo,mbrubeck/servo,akosel/servo,notriddle/servo,kindersung/servo,GyrosOfWar/servo,splav/servo,eddyb/servo,ryancanhelpyou/servo,tafia/servo,huonw/servo,jimberlage/servo,aidanhs/servo,fiji-flo/servo,pyecs/servo,evilpie/servo,eddyb/servo,runarberg/servo,mdibaiee/servo,RenaudParis/servo,j3parker/servo,RenaudParis/servo,upsuper/servo,nnethercote/servo,vks/servo,SimonSapin/servo,A-deLuna/servo,dati91/servo,pyfisch/servo,walac/servo,rixrix/servo,steveklabnik/servo,kindersung/servo,pgonda/servo,g-k/servo,RenaudParis/servo,huonw/servo,splav/servo,nnethercote/servo,fiji-flo/servo,paulrouget/servo,nerith/servo,KiChjang/servo,sadmansk/servo,tschneidereit/servo,deokjinkim/servo,saratang/servo,dsandeephegde/servo,szeged/servo,CJ8664/servo,tafia/servo,KiChjang/servo,wpgallih/servo,evilpie/servo,mt2d2/servo,fiji-flo/servo,sadmansk/servo,ryancanhelpyou/servo,canaltinova/servo,nrc/servo,zhangjunlei26/servo,RenaudParis/servo,sadmansk/servo,CJ8664/servo,rentongzhang/servo,dati91/servo,DominoTree/servo,codemac/servo,rixrix/servo,avadacatavra/servo,szeged/servo,paulrouget/servo,emilio/servo,GyrosOfWar/servo,bjwbell/servo,szeged/servo,saneyuki/servo,A-deLuna/servo,boghison/servo,A-deLuna/servo,szeged/servo,nerith/servo,saratang/servo,emilio/servo,meh/servo,evilpie/servo,zhangjunlei26/servo,wartman4404/servo,pyecs/servo,notriddle/servo,nick-thompson/servo,paulrouget/servo,DominoTree/servo,vks/servo,dvberkel/servo,brendandahl/servo,larsbergstrom/servo,nnethercote/servo,paulrouget/servo,pgonda/servo,saratang/servo,canaltinova/servo,walac/servo,youprofit/servo,pyfisch/servo,CJ8664/servo,zentner-kyle/servo,rixrix/servo,emilio/servo,caldwell/servo,notriddle/servo,vks/servo,mt2d2/servo