libvirt: add migrateToURI2 method to fakelibvirt

With the merge of

  commit ea7da5152cdca7ba674e2137c3899909995e2287
  Author: Solly Ross <sross@redhat.com>
  Date:   Tue Feb 4 14:27:51 2014 -0500

    Change listen address on libvirt live-migration

the libvirt driver uses migrateToURI2 instead of
migrateToURI. The fakelibvirt class did not define
this method so it was unable to be mocked out.

Change-Id: I74c28119c979e511cece6b839e25a40197b0e5d9
Closes-bug: 1342498
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Merge "libvirt: add migrateToURI2 method to fakelibvirt"