Fixes error in command line operation see Nickduino#25

Fixes error massage in command line operation as mentioned by @Secarius  and @ssanden in Issue Nickduino#25
_Error in MyConfig:ReadValue: 0x279621: invalid literal for int() with base 10: 'None' : myconfig.py:160_

For the object _getint()_ None ist not an valid type. But None ist used as initial value in the config file

myconfig.py

@@ -157,7 +157,10 @@ def ReadValue(self, Entry, return_type = str, default = None, section = None, No
                 elif return_type == float:
                     return self.config.getfloat(self.Section, Entry)
                 elif return_type == int:
-                    return self.config.getint(self.Section, Entry)
+                    if self.config.get(self.Section, Entry) == 'None':
+                        return None
+                    else:
+                        return self.config.getint(self.Section, Entry)
                 else:
                     self.LogErrorLine("Error in MyConfig:ReadValue: invalid type:" + str(return_type))
                     return default