object.c: no longer copy tables of classes/modules

* object.c (init_copy): no longer copy tables of classes/modules,
  since r45874 rb_mod_init_copy() does it instead.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45875 b2dd03c8-39d4-4d8f-98ff-823fe69b080e