AUTOCONF: Add missing definition of WITH_LOCAL
    
    We must arrange for every AM_CONDITIONAL to be invoked every time configure
    is run. If AM_CONDITIONAL is run conditionally (e.g., in a shell if statement),
    then the result will confuse automake.
    
    configure_dist_target_only=true ./configure
    configure: error: conditional "WITH_LOCAL" was never defined.
    Usually this means the macro was only invoked conditionally.