Fix a typo in docs/upgrading/index.rst
Fix a typo in docs/upgrading/index.rst

'protocl' -> 'protocol'
fuziontech/sentry,BuildingLink/sentry,NickPresta/sentry,vperron/sentry,jean/sentry,beni55/sentry,ngonzalvez/sentry,kevinlondon/sentry,TedaLIEz/sentry,gg7/sentry,argonemyth/sentry,zenefits/sentry,boneyao/sentry,mvaled/sentry,pauloschilling/sentry,zenefits/sentry,fotinakis/sentry,beni55/sentry,gencer/sentry,vperron/sentry,camilonova/sentry,rdio/sentry,imankulov/sentry,pauloschilling/sentry,ewdurbin/sentry,looker/sentry,zenefits/sentry,ngonzalvez/sentry,rdio/sentry,wujuguang/sentry,vperron/sentry,BayanGroup/sentry,kevinastone/sentry,JTCunning/sentry,BayanGroup/sentry,rdio/sentry,llonchj/sentry,JackDanger/sentry,felixbuenemann/sentry,nicholasserra/sentry,jean/sentry,fotinakis/sentry,jean/sentry,SilentCircle/sentry,Kryz/sentry,daevaorn/sentry,kevinlondon/sentry,daevaorn/sentry,jean/sentry,looker/sentry,alexm92/sentry,ngonzalvez/sentry,llonchj/sentry,gencer/sentry,BuildingLink/sentry,beeftornado/sentry,ifduyue/sentry,mitsuhiko/sentry,JackDanger/sentry,boneyao/sentry,gg7/sentry,BuildingLink/sentry,felixbuenemann/sentry,NickPresta/sentry,ifduyue/sentry,alexm92/sentry,zenefits/sentry,nicholasserra/sentry,Natim/sentry,zenefits/sentry,mvaled/sentry,camilonova/sentry,wong2/sentry,korealerts1/sentry,wong2/sentry,BuildingLink/sentry,ifduyue/sentry,argonemyth/sentry,1tush/sentry,gencer/sentry,Kryz/sentry,ewdurbin/sentry,looker/sentry,llonchj/sentry,argonemyth/sentry,kevinastone/sentry,JamesMura/sentry,songyi199111/sentry,korealerts1/sentry,drcapulet/sentry,fotinakis/sentry,looker/sentry,imankulov/sentry,songyi199111/sentry,jean/sentry,jokey2k/sentry,ifduyue/sentry,drcapulet/sentry,JamesMura/sentry,JTCunning/sentry,pauloschilling/sentry,rdio/sentry,1tush/sentry,fuziontech/sentry,JTCunning/sentry,TedaLIEz/sentry,BayanGroup/sentry,SilentCircle/sentry,alexm92/sentry,1tush/sentry,gencer/sentry,fuziontech/sentry,jokey2k/sentry,NickPresta/sentry,looker/sentry,Kryz/sentry,felixbuenemann/sentry,beeftornado/sentry,mitsuhiko/sentry,ewdurbin/sentry,imankulov/sentry,drcapulet/sentry,JackDanger/sentry,daevaorn/sentry,wujuguang/sentry,daevaorn/sentry,gencer/sentry,BuildingLink/sentry,mvaled/sentry,hongliang5623/sentry,jokey2k/sentry,JamesMura/sentry,SilentCircle/sentry,hongliang5623/sentry,kevinastone/sentry,fotinakis/sentry,JamesMura/sentry,nicholasserra/sentry,TedaLIEz/sentry,JamesMura/sentry,wujuguang/sentry,boneyao/sentry,hongliang5623/sentry,NickPresta/sentry,korealerts1/sentry,mvaled/sentry,kevinlondon/sentry,SilentCircle/sentry,songyi199111/sentry,Natim/sentry,mvaled/sentry,mvaled/sentry,camilonova/sentry,Natim/sentry,ifduyue/sentry,wong2/sentry,beeftornado/sentry,gg7/sentry,beni55/sentry