Fix markup

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

weblate/html/base.html

@@ -116,7 +116,7 @@
 
 <div class="content">
 <!--[if lte IE 8]>
-{% show_message "error" _("Weblate does not support Microsoft Internet Explorer 8 and older, please use some more recent browser like <a href="https://www.mozilla.org/firefox/">Firefox</a>.") %}
+{% show_message "error" _('Weblate does not support Microsoft Internet Explorer 8 and older, please use some more recent browser like <a href="https://www.mozilla.org/firefox/">Firefox</a>.') %}
 <![endif]-->
 {% if messages %}
 {% for message in messages %}