Fix resetting the probation counter.

On an integer overflow while being in low-load state the probation
counter should not be reset to zero (indicating the load limit was
violated) but rather to the lowest value representing a valid load
(being _probation + 1).

Refers to #36

ATxCommon/Monitoring/Cpu.cs

@@ -128,7 +128,7 @@ namespace ATxCommon.Monitoring
                         Log.Trace("CPU load behaving well since {0} cycles.", _behaving);
                     } else if (_behaving < 0) {
                         Log.Warn("Integer wrap around happened, resetting probation counter!");
-                        _behaving = 0;
+                        _behaving = _probation + 1;
                     }
                 }
             }