Bug#1004471: Update node-terser to latest upstream (node-terser 5)

[Yadd]

Hi,

only ruby-terser is broken by terser 5 for a bad reason, upstream uses a 
patched version of terser 5.14.

I propose to upload node-terser 5 to unstable and let Ruby Team fix 
their package.

Cheers,
Yadd