Slightly obfuscate ACM email on join page

acmsite/templates/join.html

@@ -18,6 +18,6 @@ every week!</p>
                        href="https://mywpi.wpi.edu/ACM/club_signup">https://mywpi.wpi.edu/ACM/club_signup</a></li>
     <li>Mailing List: <a
             href="mailto:acm@wpi.edu?subject=Please%20add%20me%20to%20the%20ACM%20list!&body=Hello!%0A%0AI'd%20like%20to%20be%20added%20to%20the%20ACM%20email%20list%20(acm-announce%40wpi.edu).%0A%0AThanks!">Use
-        this fancy link</a>, or email acm@wpi.edu!</li>
+        this fancy link</a>, or email acm [at] wpi [dot] edu</li>
 </ul>
 {% endblock %}