Fix service won't start if formula not upgraded to latest available version
Fix service won't start if formula not upgraded to latest available version

Fixes gapple/homebrew-services#4
Fixes homebrew/homebrew#27024

hmcfletch/homebrew-services,ne0zen/homebrew-services,tmm1/homebrew-services,Homebrew/homebrew-services,imjerrybao/homebrew-services