updates changelog for 5.8.3
updates changelog for 5.8.3

jyogi/purvar-agent,indeedops/dd-agent,cberry777/dd-agent,jyogi/purvar-agent,Wattpad/dd-agent,Wattpad/dd-agent,cberry777/dd-agent,Wattpad/dd-agent,manolama/dd-agent,takus/dd-agent,cberry777/dd-agent,jyogi/purvar-agent,manolama/dd-agent,manolama/dd-agent,jyogi/purvar-agent,takus/dd-agent,Wattpad/dd-agent,indeedops/dd-agent,Wattpad/dd-agent,indeedops/dd-agent,indeedops/dd-agent,takus/dd-agent,cberry777/dd-agent,manolama/dd-agent,cberry777/dd-agent,takus/dd-agent,takus/dd-agent,manolama/dd-agent,jyogi/purvar-agent,indeedops/dd-agent