criu: do not set network_lock if not specified

commit c4f8c87 introduced the issue.

Closes: containers#1627

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

src/libcrun/criu.c

@@ -647,7 +647,7 @@ libcrun_container_checkpoint_linux_criu (libcrun_container_status_t *status, lib
     libcriu_wrapper->criu_set_manage_cgroups_mode (cr_options->manage_cgroups_mode);
   libcriu_wrapper->criu_set_manage_cgroups (true);
 
-  if (libcriu_wrapper->criu_set_network_lock)
+  if (libcriu_wrapper->criu_set_network_lock && cr_options->network_lock_method > 0)
     libcriu_wrapper->criu_set_network_lock (cr_options->network_lock_method);
 
   ret = libcriu_wrapper->criu_dump ();