update: suppress warning about missing FETCH_HEAD
update: suppress warning about missing FETCH_HEAD

Fixes #671.

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