Prebid core: fix logic detecting if prebid is already loaded (#8549)
Prebid core: fix logic detecting if prebid is already loaded (#8549)


PubWise/Prebid.js,ImproveDigital/Prebid.js,PubWise/Prebid.js,prebid/Prebid.js,prebid/Prebid.js,HuddledMasses/Prebid.js,gumgum/Prebid.js,prebid/Prebid.js,ImproveDigital/Prebid.js,PubWise/Prebid.js,gumgum/Prebid.js,ImproveDigital/Prebid.js,HuddledMasses/Prebid.js,gumgum/Prebid.js,HuddledMasses/Prebid.js