AuTest extension: check for unrecognized configurations

This adds a trafficserver AuTest extension check to verify that the
tester did not accidentally add an unrecognized configuration option.

Author: bneradt

tests/gold_tests/autest-site/trafficserver.test.ext

@@ -187,6 +187,9 @@ def MakeATSProcess(obj, name, command='traffic_server', select_ports=True,
         "ERROR:", "diags.log should not contain errors")
     p.Disk.diags_log.Content += Testers.ExcludesExpression(
         "FATAL:", "diags.log should not contain errors")
+    p.Disk.diags_log.Content += Testers.ExcludesExpression(
+        "Unrecognized configuration value",
+        "diags.log should not contain a warning about an unrecognized configuration")
 
     if command == "traffic_manager":
         fname = "manager.log"