nodejs: Remove mksnapshot from emulator builds

:Release Notes:
Emulator builds of Node.js no longer call mksnapshot.

:Detailed Notes:
Emulator builds of Node.js no longer call mksnapshot. This will
need to be revisited for performance reasons, but is needed to get
the emulator build working again.

:Testing Performed:
Node.js built with --without-snapshot runs, build without segfaults on
startup.

:QA Notes:

:Issues Addressed:
[GF-42389] Node services appear to be broken
[GF-42545] CCC: nodejs=r5

Open-webOS-DCO-1.0-Signed-off-by: Mark Bessey <mark.bessey@lge.com>
Change-Id: I79915ec77fd4f515e5ed4340bf26356a360ca410
Reviewed-on: https://g2g.palm.com/3662
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Tested-by: Susan Montooth <susan.montooth@lge.com>