use logo in email base template

templates/emails/base.html

@@ -449,7 +449,7 @@
         <tr>
           <td class="email-masthead" style="word-break: break-word; font-family: Helvetica, Arial, sans-serif; font-size: 16px; text-align: center; padding: 25px 0;" align="center">
             <a href="https://simplelogin.io" class="f-fallback email-masthead_name" style="color: #A8AAAF; font-size: 16px; font-weight: bold; text-decoration: none; text-shadow: 0 1px 0 white;">
-              SimpleLogin
+              <img src="https://simplelogin.io/logo.png" style="width: 150px; margin: auto">
             </a>
           </td>
         </tr>