Better guard against race condition when cleaning up dead riak connections (#4021)
Better guard against race condition when cleaning up dead riak connections (#4021)

Fixes SENTRY-1JQ
zenefits/sentry,beeftornado/sentry,mvaled/sentry,BuildingLink/sentry,fotinakis/sentry,looker/sentry,zenefits/sentry,looker/sentry,gencer/sentry,gencer/sentry,BuildingLink/sentry,mvaled/sentry,alexm92/sentry,JamesMura/sentry,JamesMura/sentry,gencer/sentry,fotinakis/sentry,JamesMura/sentry,jean/sentry,fotinakis/sentry,ifduyue/sentry,gencer/sentry,mvaled/sentry,mvaled/sentry,gencer/sentry,BuildingLink/sentry,mvaled/sentry,jean/sentry,ifduyue/sentry,zenefits/sentry,ifduyue/sentry,alexm92/sentry,beeftornado/sentry,fotinakis/sentry,mvaled/sentry,JamesMura/sentry,JamesMura/sentry,JackDanger/sentry,looker/sentry,JackDanger/sentry,looker/sentry,alexm92/sentry,BuildingLink/sentry,looker/sentry,jean/sentry,jean/sentry,beeftornado/sentry,zenefits/sentry,jean/sentry,JackDanger/sentry,BuildingLink/sentry,zenefits/sentry,ifduyue/sentry,ifduyue/sentry