Fix org-duration-to-minutes call on ox-taskjuggler

* contrib/lisp/ox-taskjuggler.el (org-taskjuggler--build-task): Fix
  typo.

TINYCHANGE

contrib/lisp/ox-taskjuggler.el

@@ -861,7 +861,7 @@ a unique id will be associated to it."
      (and complete (format "  complete %s\n" complete))
      (and effort
           (format "  effort %s\n"
-                  (let* ((minutes (org-duration-minutes effort))
+                  (let* ((minutes (org-duration-to-minutes effort))
                          (hours (/ minutes 60.0)))
                     (format "%.1fh" hours))))
      (and priority (format "  priority %s\n" priority))