BibUpload: fixed crash when merging MARC into bibdoc
BibUpload: fixed crash when merging MARC into bibdoc

* When merging MARC into bibdocfile structure, if a URL is resolved
  to a docname that is not actually attached to the given record an
  exception is raised. This exception is now catched and a warning
  is simply issued.

inveniosoftware/invenio,tiborsimko/invenio,inveniosoftware/invenio,tiborsimko/invenio