fix typo

* lisp/org.el (org-babel-load-languages): Forgot to capitalize "j".

lisp/org.el

@@ -252,7 +252,7 @@ requirements) is loaded."
 		 (const :tag "Gnuplot" gnuplot)
 		 (const :tag "Haskell" haskell)
 		 (const :tag "IO" io)
-		 (const :tag "J" j)
+		 (const :tag "J" J)
 		 (const :tag "Java" java)
 		 (const :tag "Javascript" js)
 		 (const :tag "LaTeX" latex)