ox-html: Remove duplicate option in back-end

* lisp/ox-html.el (html): Remove spurious :html-link-use-abs-url option.

Reported-by: Arun Isaac <arunisaac@systemreboot.net>
<http://permalink.gmane.org/gmane.emacs.orgmode/108952>

lisp/ox-html.el

@@ -117,7 +117,6 @@
     (:html-link-home "HTML_LINK_HOME" nil org-html-link-home)
     (:html-link-up "HTML_LINK_UP" nil org-html-link-up)
     (:html-mathjax "HTML_MATHJAX" nil "" space)
-    (:html-link-use-abs-url nil "html-link-use-abs-url" org-html-link-use-abs-url)
     (:html-postamble nil "html-postamble" org-html-postamble)
     (:html-preamble nil "html-preamble" org-html-preamble)
     (:html-head "HTML_HEAD" nil org-html-head newline)