Use glyphicon load icon

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/html/zen-units.html

@@ -12,7 +12,7 @@
 {% format_translation unit.0.context search_match=search_query %}
 </td>
 <td>
-<img src="{% get_media_prefix %}loading.gif" id="loading-{{ unit.0.checksum }}" style="display: none" />
+<span id="loading-{{ unit.0.checksum }}"  class="glyphicon glyphicon-refresh glyphicon-spin" style="display: none"></span>
 <span id="messages-{{ unit.0.checksum }}" class="inline-message"></span>
 <a href="{{ unit.0.get_absolute_url }}" class="menu-float small-button button" title="{% trans "Open in full editor" %}">{% trans "Edit" %}</a>
 </td>

weblate/html/zen.html

@@ -26,10 +26,10 @@
 </span>
 {% endif %}
 
-<table class="zen">
+<table class="zen table">
 <tfoot>
 <tr><td colspan="3" class="loading-icon">
-<img src="{% get_media_prefix %}loading.gif" id="loading-next" style="display: none" />
+<span id="loading-next" class="glyphicon glyphicon-refresh glyphicon-spin" style="display: none"></span>
 <a href="{% url 'load_zen' project=object.subproject.project.slug subproject=object.subproject.slug lang=object.language.code %}?sid={{ search_id }}" class="hidden" id="zen-load" data-offset="0"></a>
 <a href="{% url 'js-lock' project=object.subproject.project.slug subproject=object.subproject.slug lang=object.language.code %}" class="hidden" id="js-lock"></a>
 </td></tr>