Reduce re.match to official name only

no_ipv4_here/templates/no_ipv4_here/index.html

@@ -53,15 +53,16 @@
     {% if domain != "" %}
     The site you tried to access is not reachable by IPv4.
     To access <a href="{{ back_to_url }}" target="_blank">{{ domain }}</a>
-    {% else %}this part of the Internet{% endif %}, you need to enable
-    IPv6 on your computer.
+    {% else %}this part of the Internet{% endif %},
+    you need to enable IPv6 on your computer.
+    <br>
     Find
     out
     <a href="https://ungleich.ch/en-us/cms/blog/2019/02/05/how-to-get-ipv6/">
       how to enable IPv6</a>
     or
-    <a href="https://redmine.ungleich.ch/projects/open-infrastructure/wiki/How_to_disable_IPv4_on_your_website">How
-    to use this service for your IPv6 only service.</a>
+    <a href="https://redmine.ungleich.ch/projects/open-infrastructure/wiki/How_to_disable_IPv4_on_your_website">how
+    to use this service</a> for your IPv6 only service.
   </p>
 </div>
 <footer class="center">

no_ipv4_here/views.py

@@ -2,6 +2,7 @@ from urllib.parse import urlsplit
 
 from django.views.generic import TemplateView
 
+import re
 
 # Create your views here.
 
@@ -16,7 +17,9 @@ class IndexView(TemplateView):
         if "back_to" in self.request.GET:
             back_to_url = self.request.GET["back_to"]
         elif 'HTTP_HOST' in self.request.META:
-            back_to_url = "http://{}".format(self.request.META['HTTP_HOST'])
+            # Exclude ourselves
+            if not re.match("^no-ipv4-here.ungleich.ch", self.request.META['HTTP_HOST']):
+                back_to_url = "http://{}".format(self.request.META['HTTP_HOST'])
         context['back_to_url'] = back_to_url
         if back_to_url != "":
             context['domain'] = (urlsplit(back_to_url)).netloc