Apport can't parse release codename in xorg

In UNR Lucid Alpha 3 Apport crashes after ubuntu-bug netbook-launcher with:

hook /usr/share/apport/package-hooks//source_xorg.py crashed:
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/apport/report.py", line 639, in add_hooks_info
    symb['add_info'](self)
  File "/usr/share/apport/package-hooks//source_xorg.py", line 29, in add_info
    codename = command_output(['lsb_release','-c']).split(": ")[1]
IndexError: list index out of range

The code is splitting on a colon followed by a space, but the string lsb_release contains a tab.

The safest thing is to only split on the colon (if it exists) and then trim the result.