FIX: load default certificates for letsencrypt and other normal certs

src/caosdb/connection/connection.py

@@ -197,6 +197,8 @@ class _DefaultCaosDBServerConnection(CaosDBServerConnection):
                                           "`{}`: {}".format(config["cacert"],
                                                             exc))
 
+        context.load_default_certs()
+
         if "url" in config:
             parsed_url = parse_url(config["url"])
             host = parsed_url.netloc