[SoftwareUpdate] Fix TypeError crash

16:33:13.4786 Traceback (most recent call last):
16:33:13.4791   File "/usr/lib/enigma2/python/Components/Ipkg.py", line 120, in cmdFinished
16:33:13.4813     self.callCallbacks(self.EVENT_DONE)
16:33:13.4815   File "/usr/lib/enigma2/python/Components/Ipkg.py", line 181, in callCallbacks
16:33:13.4833     callback(event, param)
16:33:13.4835   File "/usr/lib/enigma2/python/Screens/SoftwareUpdate.py", line 276, in ipkgCallback
16:33:13.4864     if self.total_packages > 150:
16:33:13.4869 TypeError: '>' not supported between instances of 'NoneType' and 'int'

lib/python/Screens/SoftwareUpdate.py

@@ -273,7 +273,7 @@ def ipkgCallback(self, event, param):
 				elif config.softwareupdate.updateisunstable.value == '0':
 					self.total_packages = len(self.ipkg.getFetchedList())
 					message = _("Do you want to update your %s %s ?") % (getMachineBrand(), getMachineName()) + "\n(" + (ngettext("%s updated package available", "%s updated packages available", self.total_packages) % self.total_packages) + ")"
-				if self.total_packages > 150:
+				if self.total_packages is not None and self.total_packages > 150:
 					message += " " + _("Reflash recommended!")
 				if self.total_packages:
 					global ocram