lxc: Refresh capabilities on virConnectGetCapabilities
lxc: Refresh capabilities on virConnectGetCapabilities

While not as critical as in qemu driver, there are still some
runtime information we report in capabilities XML that might
change throughout time. For instance, onlined CPUs (which affects
reported L3 cache sizes).

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Erik Skultety <2c14d38fa47c8799f1b9c16280abe27f8edfec6e@redhat.com>

jardasgit/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,jfehlig/libvirt,crobinso/libvirt,nertpinx/libvirt,jardasgit/libvirt,eskultety/libvirt,jardasgit/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,eskultety/libvirt,libvirt/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,olafhering/libvirt,eskultety/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,crobinso/libvirt,olafhering/libvirt,jfehlig/libvirt,olafhering/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,andreabolognani/libvirt,jardasgit/libvirt,zippy2/libvirt,eskultety/libvirt,andreabolognani/libvirt,libvirt/libvirt,fabianfreyer/libvirt,libvirt/libvirt,crobinso/libvirt,fabianfreyer/libvirt,eskultety/libvirt,zippy2/libvirt,zippy2/libvirt,jardasgit/libvirt,nertpinx/libvirt