“ Nothing in this subsection shall prevent the President, by and with the advice of the Senate, from appointing an individual, other than the incumbent Director of the Federal Bureau of Investigation, to a 10-year term of service subject to the provisions of subsection (b) after the date of enactment of this subsection. ‘‘ (2) The individual who is the incumbent in the office of the Director of the Federal Bureau of Investigation on the date of enactment of this subsection may not serve as Director after September 4, 2013. ”