Unbreak ./configure
    
    ./configure at least from 1.5.13 is failing on Ubuntu Oneiric.
    
    The node ``Conditionals'' of automake manual states:
    
    Note that you 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'.
    
    So the trick is to run AM_CONDITIONAL unconditionally.