gvfs freeze break request - gphoto2 backend

[Alexander Larsson <alexl redhat com>]

I recently fixed an issue in the gphoto backend affecting some canon
cameras. It turns out that it exposes two stores in one device, but one
of the stores is broken. So, we're ignoring the broken store. 
However, it turns out i missed one place were we need to ignore it too:

Bug: http://bugzilla.gnome.org/show_bug.cgi?id=570888
Patch: http://bugzilla.gnome.org/attachment.cgi?id=130451&action=view

Ignore the daemon/gvfsbackendcomputer.c part of the patch, thats already
commited now.