Hi Guix!

Sadly it's a little complicated to update node to the current 14.x
series, see https://lists.gnu.org/archive/html/guix-patches/2020-07/msg00965.html

In the meantime though, we can update the 10.x series still, it's in
maintenance mode, but still supported until April 2021 [0].

Note that this version expects symbols that are only in nghttp2 1.41 so
we need to explicitly update it instead of relying on grafting otherwise
it doesn't build.

Thanks!
Pierre