redefine collect_exts_file_info in OCaml easyblock, since fetch_exten…

…sion_sources was deprecated in easybuilders/easybuild-framework#3860

easybuild/easyblocks/o/ocaml.py

@@ -133,7 +133,7 @@ def prepare_for_extensions(self):
  self.cfg['exts_filter'] = EXTS_FILTER_OCAML_PACKAGES
  super(EB_OCaml, self).prepare_for_extensions()
 
- def fetch_extension_sources(self, *args, **kwargs):
+ def collect_exts_file_info(self, *args, **kwargs):
  """Don't fetch extension sources, OPAM takes care of that (and archiving too)."""
  return [{'name': ext_name, 'version': ext_version} for ext_name, ext_version in self.cfg['exts_list']]