Merge branch 'translation_punctuation' into 'master'

Fix punctuation discrepancies in the translations

See merge request !871

website/thaliawebsite/templates/403.html

 {% extends "error.html" %}
 {% load i18n %}
 
-{% block error_message %}{% trans "403: Permission denied." %}<br>
+{% block error_message %}{% trans "403: Permission denied" %}<br>
 
 {{ exception }}
 {% endblock %}

website/thaliawebsite/templates/singlepages/styleguide.html

@@ -135,7 +135,7 @@
     <ul>
         <li>{% trans "The top title is <strong>always</strong> 'THALIA'." %}</li>
         <li>{% trans "Always use 2 or 3 lines. No more, no less." %}</li>
-        <li>{% trans "The text is vertically centered relative to the T" %}</li>
+        <li>{% trans "The text is vertically centered relative to the T." %}</li>
         <li>{% trans "The horizontal distance between the text lines and the T is always the same." %}</li>
     </ul>
 </p>