doctor: ignore case when checking PATH for config scripts
doctor: ignore case when checking PATH for config scripts

Fixes Homebrew/homebrew#14752.

Signed-off-by: Jack Nagel <43386ce32af96f5c56f2a88e458cb94cebee3751@gmail.com>

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