Invoke curl with -f in nvs.sh

[rkrisztian]

With arm64 as a new platform supported by Node v16, I've noticed that if I want to use NVS in a project that still requires Node v14, nvs use will behave weirdly:

$ nvs use
Downloading NVS from https://github.com/jasongin/nvs
Downloading bootstrap node from https://nodejs.org/dist/v14.15.5/node-v14.15.5-darwin-arm64.tar.xz
-#O=#    #       #

For an experienced curl user, the above output should be fairly recognizable that something went wrong. However, for the average user, and for diagnostic purposes, I think it should also tell more, like what kind of error occurred.

The curl flag -f added to nvs.sh will make curl more scripting compatible, i.e. solve two problems:

• If there's an error, we will see why, like curl: (22) The requested URL returned error: 404.
• No archive file will be created with the content of a HTML error page, which is invalid. (Probably not an issue given you also perform hash checks.)

(Windows scripts do not seem to be affected.)