Prevent race condition during inline gilding

The gold-button submits the form at the same time that setGildingProperties is
called, so this disables the submit function and manually calls submit for
buttons that have a form parent (creddits and PayPal). This should prevent the
locked payment blob errors.

r2/r2/public/static/js/gold.js

@@ -168,7 +168,9 @@ r.gold = {
           r.analytics.fireFunnelEvent('gold', 'checkout', vendor);
         }
 
-        $.request('modify_payment_blob.json', {code: code, signed: signed, message: giftmessage})
+        $.request('modify_payment_blob.json', {code: code, signed: signed, message: giftmessage}, function() {
+          $button.parents('form').submit();
+        });
     },
 
     // When spending creddits, update the templates we use to generate the gilding form to display the

r2/r2/templates/goldpayment.html

@@ -123,7 +123,7 @@
         data-vendor="creddits">
     <input type="hidden" name="months" value="${thing.months}">
     <input type="hidden" name="passthrough" value="${thing.passthrough}" class="passthrough">
-    <button class="btn gold-button"><span class="snoo-head"></span>${_("creddits")}</button>
+    <button class="btn gold-button" type="button"><span class="snoo-head"></span>${_("creddits")}</button>
     <span class="status">
       <span class="remaining" data-current="${thing.months}" data-total="${thing.user_creddits}" data-template="${websafe(_ws('(use %(current)s of your %(total)s creddits)')) % dict(current='<%- current %>', total='<%- total %>')}">
       </span>
@@ -141,7 +141,7 @@
       <input type="hidden" name="quantity" value="${thing.quantity}">
     %endif
     <input type="hidden" name="hosted_button_id" value="${thing.paypal_buttonid}">
-    <button type="submit" class="btn gold-button">${_("PayPal")}</button>
+    <button type="submit" class="btn gold-button" type="button">${_("PayPal")}</button>
   </form>
 </%def>