ajax: Fix wrong ajax setting name from beforeSubmit to beforeSend.

The beforeSubmit function was a feature of the jquery-form plugin that
we removed months ago; the appropriate similar feature of jQuery's
built-in AJAX library is beforeSend.

static/js/invite.js

@@ -39,7 +39,7 @@ function submit_invitation_form() {
     channel.post({
         url: "/json/invites",
         data: data,
-        beforeSubmit: function () {
+        beforeSend: function () {
             reset_error_messages();
             // TODO: You could alternatively parse the textarea here, and return errors to
             // the user if they don't match certain constraints (i.e. not real email addresses,

static/js/settings_account.js

@@ -329,7 +329,7 @@ exports.set_up = function () {
         channel.patch({
             url: "/json/settings",
             data: data,
-            beforeSubmit: function () {
+            beforeSend: function () {
                 if (page_params.realm_password_auth_enabled !== false) {
                     // FIXME: Check that the two password fields match
                     // FIXME: Use the same jQuery validation plugin as the signup form?