test-org-table: Fix spurious failure in older Emacsen

* testing/lisp/test-org-table.el (test-org-table/field-formula-outside-table):
  Older Emaacsen throw an 'error instead of 'user-error.  Catch both
  condition names to avoid spurious test failures when that happens.

testing/lisp/test-org-table.el

@@ -1577,7 +1577,9 @@ is t, then new columns should be added as needed"
 "
 	 1
 	 "#+TBLFM: @1$2=5")
-      ('user-error t)))
+      ('user-error t)
+      ;; Older Emacsen will throw an 'error instead of 'user-error.
+      ('error t)))
 
   (let ((org-table-formula-create-columns t))