test_versioninfo fails when system has bzr 2.4

[William Grant]

bzr 2.4 changed the revno version-info field from an int to a str. This breaks test_versioninfo, which compares it to an int.

bzr-version-info.py is built using the system bzr, so it affects anywhere with system bzr 2.4. Not sure whether we can just fix the test, or if there is more fallout.

Failure in test test_out_of_tree_versioninfo_access (lp.app.tests.test_versioninfo.TestVersionInfo)
Traceback (most recent call last):
  File "/usr/lib/python2.6/unittest.py", line 279, in run
    testMethod()
  File "/home/wgrant/launchpad/lp-branches/distribution-getFileByName-die/lib/lp/app/tests/test_versioninfo.py", line 24, in test_out_of_tree_versioninfo_access
    self.assertEquals(revno, int(output))
  File "/usr/lib/python2.6/unittest.py", line 350, in failUnlessEqual
    (msg or '%r != %r' % (first, second))
AssertionError: '13788' != 13788