Wrap url fetching in a lock
Wrap url fetching in a lock

Fixes GH-1915

daevaorn/sentry,nicholasserra/sentry,BayanGroup/sentry,imankulov/sentry,looker/sentry,jean/sentry,kevinlondon/sentry,JamesMura/sentry,BayanGroup/sentry,looker/sentry,alexm92/sentry,gencer/sentry,ifduyue/sentry,JamesMura/sentry,BuildingLink/sentry,mitsuhiko/sentry,mitsuhiko/sentry,alexm92/sentry,imankulov/sentry,kevinlondon/sentry,BayanGroup/sentry,daevaorn/sentry,Kryz/sentry,looker/sentry,gencer/sentry,ifduyue/sentry,JamesMura/sentry,Kryz/sentry,jean/sentry,ifduyue/sentry,jean/sentry,JamesMura/sentry,mvaled/sentry,jean/sentry,zenefits/sentry,Natim/sentry,BuildingLink/sentry,gencer/sentry,zenefits/sentry,ngonzalvez/sentry,alexm92/sentry,jean/sentry,BuildingLink/sentry,beeftornado/sentry,BuildingLink/sentry,zenefits/sentry,zenefits/sentry,korealerts1/sentry,zenefits/sentry,fotinakis/sentry,felixbuenemann/sentry,JamesMura/sentry,mvaled/sentry,Kryz/sentry,nicholasserra/sentry,gencer/sentry,looker/sentry,fotinakis/sentry,mvaled/sentry,ngonzalvez/sentry,JackDanger/sentry,mvaled/sentry,nicholasserra/sentry,JackDanger/sentry,Natim/sentry,looker/sentry,gencer/sentry,ifduyue/sentry,ifduyue/sentry,korealerts1/sentry,beeftornado/sentry,daevaorn/sentry,ngonzalvez/sentry,felixbuenemann/sentry,felixbuenemann/sentry,BuildingLink/sentry,mvaled/sentry,beeftornado/sentry,fotinakis/sentry,korealerts1/sentry,mvaled/sentry,imankulov/sentry,Natim/sentry,fotinakis/sentry,daevaorn/sentry,kevinlondon/sentry,JackDanger/sentry