Hi there,

Attached patch should take care of mistakenly double-escaped links as
reported by Jeff Horn in <http://article.gmane.org/gmane.emacs.orgmode/48731>.

This patch might break `org-open-at-point' for some users if the
target application does not deal with (possibly) unescaped URLs. The
alternative to the guesswork would require parsing und analyzing the
link and its components (path, query, fragment) and check for
characters that absolutely need escaping depeding on the link type.

Hopefully this solution is good enough.

Best,
  -- David