Hide plugin help when set to None

monitoringplugin.py

@@ -66,6 +66,8 @@ class MonitoringPlugin(object):
 
 
 	def add_cmdlineoption(self, shortoption, longoption, dest, help, **kwargs):
+		if help == None:
+			help = optparse.SUPPRESS_HELP
 		self.__optparser.add_option(shortoption, longoption, dest=dest, help=help, **kwargs)