cmake ARPACK_HAS_ARSECOND examples

merzlab/QUICK cmake/FindARPACK.cmake :42 

unset(ARPACK_HAS_ARSECOND CACHE)

Amber-MD/cpptraj cmake-cpptraj/ThirdPartyTools/FindARPACK.cmake :42 

unset(ARPACK_HAS_ARSECOND CACHE)