[Test] One more suspicious fix for settings tests

test/functional/configs/settings.conf

@@ -45,7 +45,7 @@ settings {
       "Test" = "passed";
     }
 
-    expression = 'user || from || hostname || selector:1 || header:mime_version || header:custom_header || request_header:test'
+    expression = 'user || from || hostname || selector:1 || header:mime_version || header:custom_header || header:content_transfer_encoding || request_header:test'
     apply {
       symbols_enabled {
         SIMPLE_VIRTUAL = 10.0;