When deactivated, `nvm_version` returns the global `node` version

I have `node 0.10.26` installed from source, and `nvm use 0.10.26` as well. When I run `nvm deactivate`, and then `nvm uninstall 0.10.26`, I get a message about not uninstalling the currently active node version.

This is because `nvm_version` is calling `node -v` which means it's falling back to the non-nvm node executable.