Just weeks after it was closed by regulators and taken over by State Bank of Texas, Seaway Bank & Trust — the Chicago bank that runs the former Legacy Bank branch in Milwaukee’s central city — is now being sold to a North Carolina credit union, according to Crain’s Chicago Business. Self-Help Federal Credit Union of Greensboro, N.C., is buying Seaway Bank from the Dallas-based State Bank of Texas. The credit union specializes in lending to low-income and minority customers and already owns…