ovirt-foreign-menu: Fix warnings on Rawhide
    
    gmaovirt-foreign-menu.c: In function 'storage_domains_fetched_cb':
    ovirt-foreign-menu.c:721:9: error: format not a string literal and no format arguments [-Werror=format-security]
      721 |         g_debug(msg);
          |         ^~~~~~~
    ovirt-foreign-menu.c:722:9: error: format not a string literal and no format arguments [-Werror=format-security]
      722 |         g_task_return_new_error(task, OVIRT_ERROR, OVIRT_ERROR_FAILED, msg);
          |         ^~~~~~~~~~~~~~~~~~~~~~~
    cc1: some warnings being treated as errors
    gmake[3]: *** [Makefile:963: libvirt_viewer_la-ovirt-foreign-menu.lo] Error 1
    gmake[2]: *** [Makefile:647: all] Error 2
    gmake[1]: *** [Makefile:482: all-recursive] Error 1
    make: *** [Makefile:410: all] Error 2
    error: Bad exit status from /var/tmp/rpm-tmp.f14Lmj (%build)
    
    Errors have been caught by https://ci.centos.org/job/virt-viewer-rpm/systems=libvirt-fedora-rawhide/589/
    
    Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>
    Acked-by: Eduardo Lima (Etrunko) <etrunko@redhat.com>