tests: ignore pending GET requests when waiting for ajax

With apparition redirects will not contain response_parts
and therefore are interpreted as pending.

There does not seem to be a public interface
for checking if a request already returned a redirect response.

Since all the requests in question were GET requests
and they should not change state
ignore them when waiting for pending requests.

test/helpers/integration/javascript/ajax_pending.rb

@@ -53,7 +53,8 @@ module AjaxPending
     # let's not worry about missing images
     pending_requests.reject do |req|
       req.url.include?('.png') or
-        req.url.include?('.jpg')
+        req.url.include?('.jpg') or
+        req.method == 'GET'
     end
   end