Remove link to mitm.watch (#453)

Site was shut down.

Fixes issue #452.

Author: alesandroortiz

domains/misc/badssl.com/index.html

@@ -162,7 +162,6 @@ <h2 id="defunct"><span class="emoji">☠️</span>Defunct</h2>
     <h2 id="test-suites"><span class="emoji">🛠</span>Test Suites</h2>
     <a href="https://testsafebrowsing.appspot.com/" target="_blank" class="external"><span class="icon"></span>Safe Browsing Tests</a>
     <a href="https://www.ssllabs.com/ssltest/viewMyClient.html" target="_blank" class="external"><span class="icon"></span>SSL Labs Client Test</a>
-    <a href="https://mitm.watch/" target="_blank" class="external"><span class="icon"></span>mitm.watch</a>
   </div>
   <div id="preload" style="width: 0; height: 0;">
     <!-- <link rel=preload> results in warnings in Chrome: https://crbug.com/661055 -->