Merge branch 'klaar36-production-patch-83549' into 'production'

Update cplusplus.rules, duckduck error page

See merge request !42

files/squid/helpers/rules.d/cplusplus.rules

@@ -25,3 +25,4 @@
 ^https?://duckduckgo\.com/.*\.css                       true
 ^https?://duckduckgo\.com/.*\.js                        true
 ^https?://duckduckgo\.com/.*\.js\?.=.*                  true
+^https?://duckduckgo\.com/50x-tq.html\?tq=.*            true