Merge pull request #3324 from zunware/patch-2

Fixes messages colors.

geonode/templates/_messages.html

 {% if messages %}
 <div id="user_messages">
     {% for message in messages %}
-    <div class="alert alert-block announcement alert-warning">
+    <div class="alert alert-block announcement {% if message.tags %}alert-{{message.tags}}{% else %}alert-warning{% endif %}">
         <a type="button" class="close" data-dismiss="alert" data-dismiss-url="#" href="#">×</a>
         <p{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</p>
     </div>