As long as it is only a nick then the cell will ligate it find. It is much the same as when you do a ligation with dephosphorylated DNA, one strand is ligated but the other not resulting in a nick on either side of your insert. Those will also transform and be repaired.

Does only xl1 blue cells ligate the nick or the other cells such as dh5 alpha also can ligate it?

Any strain. this is just normal DNA repair, during DNA replication there are nicks all over the discontinuous strand.