Skip GCC version check
Skip GCC version check

This is not necessary.

In addition,
1. Avoid an error when `formula.tap` is `nil`.
2. Use the more suggestive `gcc.dep.rpaths.migrated` as the setting
   name.

Homebrew/brew,Homebrew/brew,nandub/brew,JCount/brew,MikeMcQuaid/brew,nandub/brew,JCount/brew,nandub/brew,Homebrew/brew,JCount/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,nandub/brew,Homebrew/brew,JCount/brew,MikeMcQuaid/brew