framework/native/docs: remove doc footer for jd output

Change-Id: Ib65a436f4846eb5c02e42c6f1cbda5eab58c68ab
diff --git a/docs/Doxyfile b/docs/Doxyfile
index ce12d81..46d6d84 100644
--- a/docs/Doxyfile
+++ b/docs/Doxyfile
@@ -948,7 +948,7 @@
 # each generated HTML page. If it is left blank doxygen will generate a 
 # standard footer.
 
-HTML_FOOTER            = 
+HTML_FOOTER            = $(HTML_FOOTER)
 
 # The HTML_STYLESHEET tag can be used to specify a user-defined cascading 
 # style sheet that is used by each HTML page. It can be used to