compat: Prevent spell-checking citation

* lisp/org-compat.el (org--flyspell-object-check-p): Do not
spell-check citation and citation-reference objects.

Reported-by: Rudolf Adamkovič <salutis@me.com>
<http://lists.gnu.org/r/emacs-orgmode/2022-01/msg00434.html>

lisp/org-compat.el

@@ -1049,9 +1049,9 @@ ELEMENT is the element at point."
     (cl-case (org-element-type object)
       ;; Prevent checks in links due to keybinding conflict with
       ;; Flyspell.
-      ((code entity export-snippet inline-babel-call
-	     inline-src-block line-break latex-fragment link macro
-	     statistics-cookie target timestamp verbatim)
+      ((citation citation-reference code entity export-snippet inline-babel-call
+	         inline-src-block line-break latex-fragment link macro
+	         statistics-cookie target timestamp verbatim)
        nil)
       (footnote-reference
        ;; Only in inline footnotes, within the definition.