Fix reconnecting to libvirt.

The right logic was in place for dealing with losing a connection to
libvirt and reconnecting.  However, it was observed that we actually get
VIR_ERR_INTERNAL_ERROR, VIR_FROM_RPC after restarting libvirtd.  The
code is just updated to deal with INTERNAL_ERROR.

Fix bug 1154473.

Change-Id: Idf4abf3fe485cf534f1732e4340fc35652fec003
Merge "Fix reconnecting to libvirt."