adding ob-calc to org-babel-load-languages

* lisp/org.el (org-babel-load-languages): adding calc

lisp/org.el

@@ -147,6 +147,7 @@ requirements) is loaded."
 		 (const :tag "C" C)
 		 (const :tag "R" R)
 		 (const :tag "Asymptote" asymptote)
+		 (const :tag "Calc" calc)
 		 (const :tag "Clojure" clojure)
 		 (const :tag "CSS" css)
 		 (const :tag "Ditaa" ditaa)