lisp/ob.el: Don't modify babel info when hashing it

* lisp/ob.el (org-babel-sha1-hash): Don't modify info argument by
side-effect when sorting result-params list.

copy-sequence only does shallow copies, so if we're going to modify a
sub-list, we need to make sure we copy it first.

lisp/ob.el

@@ -767,7 +767,7 @@ the current subtree."
 				  (cond
 				   ((and (listp v) ; lists are sorted
 					 (member (car arg) '(:result-params)))
-				    (sort v #'string<))
+				    (sort (copy-sequence v) #'string<))
 				   ((and (stringp v) ; strings are sorted
 					 (member (car arg) '(:results :exports)))
 				    (mapconcat #'identity (sort (split-string v)