[MM-45135] - Mattermost Logo is outdated in Cloud welcome email (#20548)

templates/cloud_welcome_email.html

@@ -21,7 +21,7 @@
                                 style="margin-bottom: 30px;">
                                 <tr>
                                     <td style="padding: 20px 20px 10px; text-align:center;">
-                                        <img src="{{.Props.WorkSpacePath}}/static/images/logo_email_blue.png"
+                                        <img src="{{.Props.WorkSpacePath}}/static/images/logo_email_dark.png"
                                             style="height: 21.7px;" alt="logo_email_blue">
                                     </td>
                                 </tr>