zdtm: add --link-remap opt to unlink_regular00 test desc

--link-remap opt is obligatory for unlink_regular00 test.
Without it CRIU dump will fail because it won't be able to
create link remaps.
Signed-off-by: Eugene Batalov <eabatalov89@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

test/zdtm/static/unlink_regular00.desc

-{'flavor': 'ns', 'flags': 'suid crfail'}
+{'flavor': 'ns', 'flags': 'suid crfail', 'opts': '--link-remap'}