Fix printing of warnings in management UI

Author: lhoguin

deps/rabbitmq_management/priv/www/js/tmpl/login_oauth.ejs

@@ -4,7 +4,7 @@
   <div id="login-status">
     <% if (Array.isArray(warnings)) { %>
         <% for (var i = 0; i < warnings.length; i++) { %>
-        <p class="warning"><%=warnings[i]%> </p>
+        <p class="warning"><%=fmt_escape_html(warnings[i])%> </p>
         <% } %>
     <% } %>
     <% if (notAuthorized) { %>