Re: [Libguestfs] [PATCH 1/2] lib: enable the libvirt code consistently everywhere

With commit bc2b41778405cc6a376a670703ce63e3678bf1fb HAVE_LIBVIRT_BACKEND is defined based on the libvirt version (using its version macro), although libvirt.h is included only after that check: because of this, variables in the guestfs_h struct after the HAVE_LIBVIRT_BACKEND block would be used wrongly if libvirt.h was not included before guestfs-internal.h, like in the recently added available.c (all the other places using libvirt features in the handle already happened to do so).