lib/python/Plugins/SystemPlugins/SoftwareManager: more robust code this i.e. fixes:

lib/python/Plugins/SystemPlugins/SoftwareManager: more robust code this i.e. fixes:

Traceback (most recent call last):
  File "/usr/lib/enigma2/python/Tools/BoundFunction.py", line 9, in __call__
     return self.fnc(*self.args + args, **newkwargs)
   File "/usr/lib/enigma2/python/Components/Console.py", line 56, in finishedCB
     self.callbacks[name](data,retval,extra_args)
   File "/usr/lib/enigma2/python/Plugins/SystemPlugins/SoftwareManager/SoftwareTools.py", line 108, in IpkgListAvailableCB
     SoftwareTools.available_packetlist.append([name, split[1].strip(), split[2].strip()])

ref bug #383