Fixes a bug in installer registration where executable is evaluated
before entrypoints and other details are added.
***RECKLESS STDERR***
Traceback (most recent call last):
File lightning/tools/reckless, line 382, in <module>
INSTALLERS['nodejs'].add_entrypoint('{name}')
KeyError: 'nodejs'
Reported by @ksedgwic
Changelog-None