MDL-72299 mod_lti: fix html escaping when reposting cross site posts

mod/lti/classes/output/repost_crosssite_page.php

@@ -56,7 +56,7 @@ class repost_crosssite_page implements renderable, templatable {
      */
     public function __construct(string $url, array $post) {
         $this->params = array_map(function($k) use ($post) {
-            return ["key" => $k, "value" => str_replace("\"", """, $post[$k])];
+            return ["key" => $k, "value" => $post[$k]];
         }, array_keys($post));
         $this->url = $url;
     }

mod/lti/templates/repost_crosssite.mustache

@@ -37,9 +37,9 @@
     }
 
 }}
-<form action="{{{url}}}" method="POST" id="autopostme">
+<form action="{{url}}" method="POST" id="autopostme">
     {{#params}}
-    <input type="hidden" name="{{{key}}}" value="{{{value}}}">
+    <input type="hidden" name="{{key}}" value="{{value}}">
     {{/params}}
     <input type="hidden" name="repost" value="true">
 </form>