bump-formula-pr: also infer mirrors when a checksum is provided
bump-formula-pr: also infer mirrors when a checksum is provided

EricFromCanada/brew,nandub/brew,JCount/brew,EricFromCanada/brew,sjackman/homebrew,Homebrew/brew,JCount/brew,nandub/brew,MikeMcQuaid/brew,konqui/brew,claui/brew,EricFromCanada/brew,mahori/brew,vitorgalvao/brew,reitermarkus/brew,nandub/brew,sjackman/homebrew,vitorgalvao/brew,mahori/brew,nandub/brew,mahori/brew,reitermarkus/brew,Homebrew/brew,reitermarkus/brew,konqui/brew,JCount/brew,EricFromCanada/brew,mahori/brew,MikeMcQuaid/brew,reitermarkus/brew,claui/brew,JCount/brew,MikeMcQuaid/brew,Homebrew/brew,claui/brew,sjackman/homebrew,sjackman/homebrew,Homebrew/brew,MikeMcQuaid/brew,vitorgalvao/brew,konqui/brew,claui/brew,vitorgalvao/brew,konqui/brew