repo: Don't call g_hash_table_destroy on a NULL hash
repo: Don't call g_hash_table_destroy on a NULL hash

leandrosansilva/ostree,resin-io/ostree,gatispaeglis/ostree,sujitfulse/ostree,GNOME/ostree,GNOME/ostree,sujitfulse/ostree,leandrosansilva/ostree,leandrosansilva/ostree,sujitfulse/ostree,gatispaeglis/ostree,sujitfulse/ostree,gatispaeglis/ostree,gatispaeglis/ostree,resin-io/ostree,sujitfulse/ostree,GNOME/ostree,gatispaeglis/ostree,GNOME/ostree,gatispaeglis/ostree,resin-io/ostree,leandrosansilva/ostree,resin-io/ostree,GNOME/ostree,resin-io/ostree,leandrosansilva/ostree