copy_email_modal: Avoid unnecessary raw HTML description.

The context passed in web/src/stream_edit.ts
never contains any HTML formatted string for
the description, so it is safe to replace
`{{{` with `{{`.

Signed-off-by: apoorvapendse <apoorvavpendse@gmail.com>

web/templates/stream_settings/copy_email_address_modal.hbs

@@ -14,7 +14,7 @@
                 <input class="tag-checkbox" id="{{ this.name }}" type="checkbox"/>
                 <span class="rendered-checkbox"></span>
             </label>
-            <label class="inline" for="{{this.name}}">{{{this.description}}}</label>
+            <label class="inline" for="{{this.name}}">{{this.description}}</label>
         </div>
     {{/each}}
     <hr />