Issue 6769 - Avoid hardcoding the URL

pages/exceptions/image.tmpl

 title = $image Exception
 template = testcase
 
 {% set testcase_moreinfo = [
   ("Filter Options", "https://adblockplus.org/filters#options"),
 ] %}
 
 <link rel="stylesheet" href="/testcasefiles/imageexception/stylesheet.css">
 
 <section class="site-panel">
   <h2>$image Exception</h2>
   <p>Check that usage of the $image filter option in an exception filter works as expected.</p>
   <p>With the filter(s) displayed below each test case added to ABP (or with the testcase subscription installed and active), the image should not be blocked while the stylesheet should be.</p>
 </section>
 
 <section class="site-panel">
   <h2>Test case</h2>
   <p>The image should not be blocked (exception). The stylesheet should be blocked.</p>
   <div class="testcase-container">
     <div class="testcase-row">
       <h3>Image</h3><img class="testcase-image" src="/testcasefiles/imageexception/image.jpg"/>
     </div>
     <div class="testcase-row">
       <h3>Stylesheet</h3><div class="testcase-teststylesheet trap">&nbsp;</div>
     </div>
   </div>
   <h3>Filters</h3>
-  <pre>||testpages.adblockplus.org/testcasefiles/imageexception/*</pre>
-  <pre>@@testpages.adblockplus.org/testcasefiles/imageexception/$image</pre>
+  <pre>||{{ site_url|strip_proto }}/testcasefiles/imageexception/*</pre>
+  <pre>@@{{ site_url|strip_proto }}/testcasefiles/imageexception/$image</pre>
 </section>