Update the references in boot to mention GitLab instead of ghc.haskell.org
ghc-8.6.4/boot contains:
- 57: * https://ghc.haskell.org/trac/ghc/wiki/Newcomers or
- 58: * https://ghc.haskell.org/trac/ghc/wiki/Building/GettingTheSources#CloningfromGitHub
- 190: http://ghc.haskell.org/trac/ghc/wiki/Building/Using#Buildconfiguration
and boot prints the latter line. Visiting it states, the Wiki/information is moved to Gitlab.
- Update the references in boot to mention GitLab instead of ghc.haskell.org.