Improve Caching of public pages, a=chris

diff --git a/src/views/elements/WikiElement.php b/src/views/elements/WikiElement.php
index 699efac25..2ed3442da 100644
--- a/src/views/elements/WikiElement.php
+++ b/src/views/elements/WikiElement.php
@@ -2089,6 +2089,14 @@ class WikiElement extends Element implements CrawlConstants
         $no_amp_csrf_token = "";
         $no_right_amp_csrf_token = "";
         if (!empty($data['ADMIN'])) {
+            $token_string = $data[C\CSRF_TOKEN];
+            if ($group_id == C\PUBLIC_GROUP_ID ||
+                (!empty($data["GROUP"]["GROUP_ID"]) &&
+                !empty($data["GROUP"]["REGISTER_TYPE"]) &&
+                $group_id == $data["GROUP"]["GROUP_ID"]) &&
+                $data["GROUP"]["REGISTER_TYPE"] == C\PUBLIC_JOIN) {
+                $data[C\CSRF_TOKEN] = str_pad("", 11,  "0");
+            }
             $no_amp_csrf_token = C\CSRF_TOKEN . "=" . $data[C\CSRF_TOKEN];
             $no_right_amp_csrf_token =
                 "&". $no_amp_csrf_token;