HTML validation: Fix <label for="…"> references.

These must refer to the id of an existing form control; id_username
doesn’t exist and streams_to_add isn’t a form control.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

templates/zerver/app/invite_user.html

@@ -30,7 +30,7 @@
                 <div class="alert" id="dev_env_msg"></div>
                 {% endif %}
                 <div class="control-group">
-                    <label class="control-label" for="streams_to_add">{{ _('Streams they should join') }}</label>
+                    <label class="control-label">{{ _('Streams they should join') }}</label>
                     <div class="controls" id="streams_to_add"></div>
                 </div>
             </div>

templates/zerver/create_realm.html

@@ -24,7 +24,7 @@ $(function () {
                     <div class="inline-block relative">
                         <input type="text" class="email required" placeholder="{{ _("Enter your email address") }}"
                           id="email" name="email" required />
-                        <label for="id_username">{{ _('Email') }}</label>
+                        <label for="email">{{ _('Email') }}</label>
                     </div>
 
                     <button type="submit" class="new-organization-button register-button">{{ _("Create organization") }}</button>