fix detetion of previous build
fix detetion of previous build

pavel-paulau/perfrunner,hsharsha/perfrunner,pavel-paulau/perfrunner,PaintScratcher/perfrunner,couchbase/perfrunner,dkao-cb/perfrunner,dkao-cb/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,couchbase/perfrunner,EricACooper/perfrunner,hsharsha/perfrunner,PaintScratcher/perfrunner,EricACooper/perfrunner,EricACooper/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,mikewied/perfrunner,thomas-couchbase/perfrunner,pavel-paulau/perfrunner,thomas-couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,EricACooper/perfrunner,vmx/perfrunner,mikewied/perfrunner,vmx/perfrunner