update.sh: hide GITHUB_HEADERS missing output.
update.sh: hide GITHUB_HEADERS missing output.

Will only happen once but could be confusing anyway.

palxex/brew,gregory-nisbet/brew,vitorgalvao/brew,jmsundar/brew,jmsundar/brew,reelsense/brew,EricFromCanada/brew,zmwangx/brew,ilovezfs/brew,JCount/brew,claui/brew,rwhogg/brew,MikeMcQuaid/brew,zmwangx/brew,reelsense/brew,MikeMcQuaid/brew,mahori/brew,vitorgalvao/brew,JCount/brew,muellermartin/dist,pseudocody/brew,konqui/brew,DomT4/brew,EricFromCanada/brew,DomT4/brew,ilovezfs/brew,tonyg/homebrew,reitermarkus/brew,amar-laksh/brew_sudo,rwhogg/brew,hanxue/linuxbrew,mgrimes/brew,hanxue/linuxbrew,alyssais/brew,sjackman/homebrew,Linuxbrew/brew,pseudocody/brew,Homebrew/brew,alyssais/brew,pseudocody/brew,nandub/brew,muellermartin/dist,Linuxbrew/brew,EricFromCanada/brew,gregory-nisbet/brew,vitorgalvao/brew,claui/brew,muellermartin/dist,vitorgalvao/brew,JCount/brew,aw1621107/brew,Homebrew/brew,DomT4/brew,sjackman/homebrew,mahori/brew,mgrimes/brew,claui/brew,palxex/brew,mahori/brew,Linuxbrew/brew,Linuxbrew/brew,tonyg/homebrew,aw1621107/brew,ilovezfs/brew,reelsense/brew,bfontaine/brew,konqui/brew,maxim-belkin/brew,konqui/brew,amar-laksh/brew_sudo,konqui/brew,palxex/brew,aw1621107/brew,mahori/brew,tonyg/homebrew,Homebrew/brew,claui/brew,amar-laksh/brew_sudo,maxim-belkin/brew,reitermarkus/brew,nandub/brew,nandub/brew,MikeMcQuaid/brew,hanxue/linuxbrew,alyssais/brew,zmwangx/brew,nandub/brew,bfontaine/brew,JCount/brew,Homebrew/brew,maxim-belkin/brew,reitermarkus/brew,rwhogg/brew,jmsundar/brew,EricFromCanada/brew,sjackman/homebrew,MikeMcQuaid/brew,bfontaine/brew,gregory-nisbet/brew,DomT4/brew,reitermarkus/brew,mgrimes/brew,sjackman/homebrew