fix the logout button

templates/header_with_user.html

@@ -6,11 +6,13 @@
     Hello, {{ usr.username }}!
 </div>
 <div>
+    <form action="/logout" enctype="application/x-www-form-urlencoded" method="post">
         <button class="warning">
             <input type="submit" value="sign out?">
-        </form>
         </button>
+    </form>
 </div>
+
 {% else %}
 <div class="header_logged_out">
     Heya, why don't you <a href="/login">log in</a> or <a href="/signup">sign up</a>?