If any of the restrictions or obligations contained in Section 8 shall be determined by any court of competent jurisdiction to be unenforceable by reason of their extending for too great a period of time or over too great a geographical area or by reason of their being too extensive in any other respect, such provision shall be modified to be effective for the maximum period of time for which it may be enforceable and over the maximum geographical area as to which it may be enforceable and to the maximum extent in all other respects as to which it may be enforceable.