box update is now an alert notification

src/mail_templates/box_update_available.ejs

@@ -1,56 +0,0 @@
-<%if (format === 'text') { %>
-
-Dear <%= cloudronName %> Admin,
-
-Version <%= newBoxVersion %> is now available!
-
-Changelog:
-<% for (var i = 0; i < changelog.length; i++) { %>
-  * <%- changelog[i] %>
-<% } %>
-
-<% if (!hasSubscription) { -%>
-*Keep your Cloudron automatically up-to-date and secure by upgrading to a paid plan at* <%= webadminUrl %>/#/settings
-<% } -%>
-
-Powered by https://cloudron.io
-
-Sent at: <%= new Date().toUTCString() %>
-
-<% } else { %>
-
-<center>
-
-<img src="<%= cloudronAvatarUrl %>" width="128px" height="128px"/>
-
-<h3>Dear <%= cloudronName %> Admin,</h3>
-
-<div style="width: 650px; text-align: left;">
-    <p>
-        Version <b><%= newBoxVersion %></b> is now available!
-    </p>
-
-    <h5>Changelog:</h5>
-    <ul>
-    <% for (var i = 0; i < changelogHTML.length; i++) { %>
-        <li><%- changelogHTML[i] %></li>
-    <% } %>
-    </ul>
-
-    <br/>
-
-    <% if (!hasSubscription) { %>
-    <p>Keep your Cloudron automatically up-to-date and secure by upgrading to a <a href="<%= webadminUrl %>/#/settings">paid plan</a>.</p>
-    <% } %>
-
-    <br/>
-</div>
-
-<div style="font-size: 10px; color: #333333; background: #ffffff;">
-    Powered by <a href="https://cloudron.io">Cloudron</a>.
-</div>
-
-</center>
-
-<% } %>
-