Google moved their oslogin guest tools to another repository.
Point src to there, and bump to the latest version
There's now a Makefile, so we can avoid having our own custom
installPhase, and we also get manpages.
I successfully ran the oslogin tests, so assuming the google cloud
metadata server still behaves like in our test, logins should work.
I saw a nscd segfault, not sure if it's caused by this or was already
the case before.
It'd be great if someone could test this on an actual VM.