Boundary Condition for Perfect Conductor in Uniform Magnetic Field

When I was studying the perfect conductor scattering (Section 10.1) in Jackson's book, I was confused by the calculation for magnetic dipole induced by the incident wave. He simply said like "set the $\mu$=0 in equation (5.115)......"

Actually, equation (5.115) $$M=\frac{3}{\mu_0}\frac{\mu-\mu_0}{\mu+2\mu_0}B_0$$ is derived under the boundary condition that the surface current=0, i.e. the tangential component of H is continuous. But for perfect conductor, this condition is not valid. So any body can help me to figure out how can I get the magnetic dipole in this situation? Thanks.

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