Update SystemInfo.py

Traceback (most recent call last):
  File "/usr/lib/enigma2/python/mytest.py", line 714, in <module>
    Components.UsageConfig.InitUsageConfig()
  File "/usr/lib/enigma2/python/Components/UsageConfig.py", line 444, in InitUsageConfig
  File "/usr/lib/enigma2/python/Components/config.py", line 149, in addNotifier
  File "/usr/lib/enigma2/python/Components/UsageConfig.py", line 442, in wakeOnLANChanged
TypeError: coercing to Unicode: need string or buffer, bool found