Add http+https checks to validation

Author: marcoscaceres

index.html

@@ -197,9 +197,6 @@ <h4>
                 </li>
                 <li>Assert: |url| is {{URL}}.
                 </li>
-                <li>If |url|'s [=URL/scheme=] is not "http" or "https", return
-                <a>a promise rejected with</a> {{TypeError}}.
-                </li>
                 <li>Set |data| to a copy of |data|, with its {{ShareData/url}}
                 member set to the result of running the <a>URL serializer</a>
                 on |url|.
@@ -308,6 +305,9 @@ <h3>
                 </li>
                 <li>If |url| is failure, return false.
                 </li>
+                <li>If |url|'s [=URL/scheme=] is not "http" or "https", return
+                return false.
+                </li>
               </ol>
             </li>
             <li>Return true.
@@ -553,8 +553,7 @@ <h2>
             when information should be confidential, so forwarding any content
             presents a risk. In particular, the {{ShareData/title}} might be
             used by an attacker to trick a user into misinterpreting the nature
-            of the content.
-            <!--
+            of the content. <!--
               , as demonstrated in the [[Wylecial]] <a data-cite=
               "Wylecial#">proof of concept attack</a>
             -->