Fix tap completion when there aren't any taps
Fix tap completion when there aren't any taps

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