Ruby Loader segmentation fault related to Node Port test

[viferga]

Related to this commit: https://github.com/metacall/core/commit/3fb57a86d334a4b15b9c249594d3d9165f2abb81#diff-fe9caa8952071583fbfe3ea54361f8843196e62d4eeb269125b5f70494caca2fL842

I have avoided a segmentation fault when executing metacall_destroy in the Node Port test. This should be reviewed. Probably it is a double free or something like that. I prefer to leave it as a memory leak on destroy rather than a segmentation fault.