OPINION — AG — FEDERAL CREDIT UNIONS ARE NOT SUBJECT TO STATE LAW SETTING FORTH THE MAXIMUM PERMISSIBLE RATE OF INTEREST WHERE SUCH STATE LAW IS PREEMTED BY FEDERAL LAW (FEDERAL, INTEREST RATES) CITE: 12 U.S.C.A. 1757(5),12 U.S.C.A. 1785 (JOHN PAUL JOHNSON)