src: update NODE_MODULE_VERSION to 53

V8 5.6 is not API/ABI compatible with 5.5.
This commit increments NODE_MODULE_VERSION by one.

Refs: https://github.com/nodejs/CTC/blob/master/meetings/2016-09-28.md
PR-URL: https://github.com/nodejs/node/pull/10992


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>