rvm db doesn't respect autolibs=read-fail

Tested with ubuntu 12.04 (LTS):

curl -L https://get.rvm.io | bash -s head --trace --ignore-dotfiles --autolibs=read-fail --path /tmp/foo

Outputs a few errors:

tools/.rvm/scripts/db: line 3: /functions/support: No such file or directory
tools/.rvm/scripts/db: line 35: __rvm_sed: command not found
tools/.rvm/scripts/db: line 46: __rvm_sed: command not found