Fix blank invite email (#17065)

* Fix blank invite email

* Some small improvements

* Another small fix

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

templates/invite_body.html

@@ -19,7 +19,7 @@
                                         <tr>
                                             <td style="border-bottom: 1px solid #ddd; padding: 0 0 20px;">
                                                 <h2 style="font-weight: normal; margin-top: 10px;">{{.Props.Title}}</h2>
-                                                <p>{{.Html.Info}}</p>
+                                                <p>{{.HTML.Info}}</p>
                                                 <p style="margin: 30px 0 15px">
                                                     <a href="{{.Props.Link}}" style="background: #2389D7; border-radius: 3px; color: #fff; border: none; outline: none; min-width: 200px; padding: 15px 25px; font-size: 14px; font-family: inherit; cursor: pointer; -webkit-appearance: none;text-decoration: none;">{{.Props.Button}}</a>
                                                 </p>
@@ -37,7 +37,7 @@
                                                     </table>
                                                 {{end}}
                                                 <br/>
-                                                <p>{{.Html.ExtraInfo}}<br/><br/><a href='{{.Props.TeamURL}}'>{{.Props.TeamURL}}</a></p>
+                                                <p>{{.HTML.ExtraInfo}}<br/><br/><a href='{{.Props.TeamURL}}'>{{.Props.TeamURL}}</a></p>
                                             </td>
                                         </tr>
                                         <tr>